Added support for Nucleo F303RE
Added support for Nucleo F303RE

The OS_TASKCNT is set to 6, could be more.
The OS_SCHEDULERSTKSIZE is set to 112, could also be more.
The OS_CLOCK is set to 72000000 which matches the description on https://developer.mbed.org/platforms/ST-Nucleo-F303RE/

Cheers
larks/mbed,betzw/mbed-os,Marcomissyou/mbed,karsev/mbed-os,bikeNomad/mbed,catiedev/mbed-os,fpiot/mbed-ats,al177/mbed,rosterloh/mbed,c1728p9/mbed-os,ban4jp/mbed,catiedev/mbed-os,ARM-software/mbed-beetle,HeadsUpDisplayInc/mbed,nRFMesh/mbed-os,ARM-software/mbed-beetle,jpbrucker/mbed,adamgreen/mbed,dbestm/mbed,xcrespo/mbed,EmuxEvans/mbed,devanlai/mbed,pi19404/mbed,al177/mbed,masaohamanaka/mbed,RonEld/mbed,EmuxEvans/mbed,cvtsi2sd/mbed-os,rosterloh/mbed,Timmmm/mbed,dbestm/mbed,arostm/mbed-os,xcrespo/mbed,monkiineko/mbed-os,jpbrucker/mbed,adamgreen/mbed,betzw/mbed-os,logost/mbed,K4zuki/mbed,adamgreen/mbed,HeadsUpDisplayInc/mbed,NXPmicro/mbed,svastm/mbed,adamgreen/mbed,devanlai/mbed,pedromes/mbed,YarivCol/mbed-os,autopulated/mbed,andcor02/mbed-os,naves-thiago/mbed-midi,logost/mbed,infinnovation/mbed-os,monkiineko/mbed-os,jrjang/mbed,JasonHow44/mbed,arostm/mbed-os,cvtsi2sd/mbed-os,bentwire/mbed,al177/mbed,kl-cruz/mbed-os,catiedev/mbed-os,nabilbendafi/mbed,bcostm/mbed-os,jamesadevine/mbed,betzw/mbed-os,YarivCol/mbed-os,cvtsi2sd/mbed-os,c1728p9/mbed-os,larks/mbed,screamerbg/mbed,Timmmm/mbed,Archcady/mbed-os,svogl/mbed-os,bcostm/mbed-os,Tiryoh/mbed,jeremybrodt/mbed,logost/mbed,devanlai/mbed,alertby/mbed,ryankurte/mbed-os,NitinBhaskar/mbed,al177/mbed,CalSol/mbed,andreaslarssonublox/mbed,c1728p9/mbed-os,struempelix/mbed,nvlsianpu/mbed,kpurusho/mbed,kpurusho/mbed,c1728p9/mbed-os,jeremybrodt/mbed,ryankurte/mbed-os,fpiot/mbed-ats,pedromes/mbed,rosterloh/mbed,catiedev/mbed-os,adamgreen/mbed,brstew/MBED-BUILD,bikeNomad/mbed,rosterloh/mbed,Tiryoh/mbed,pi19404/mbed,hwfwgrp/mbed,rgrover/mbed,NXPmicro/mbed,rgrover/mbed,CalSol/mbed,NitinBhaskar/mbed,mnlipp/mbed,devanlai/mbed,Archcady/mbed-os,HeadsUpDisplayInc/mbed,fahhem/mbed-os,EmuxEvans/mbed,theotherjimmy/mbed,autopulated/mbed,mbedmicro/mbed,netzimme/mbed-os,autopulated/mbed,kjbracey-arm/mbed,Marcomissyou/mbed,screamerbg/mbed,netzimme/mbed-os,geky/mbed,adamgreen/mbed,JasonHow44/mbed,nabilbendafi/mbed,arostm/mbed-os,adustm/mbed,j-greffe/mbed-os,al177/mbed,svastm/mbed,NXPmicro/mbed,nabilbendafi/mbed,jeremybrodt/mbed,adustm/mbed,ryankurte/mbed-os,getopenmono/mbed,pradeep-gr/mbed-os5-onsemi,ARM-software/mbed-beetle,K4zuki/mbed,naves-thiago/mbed-midi,andcor02/mbed-os,pbrook/mbed,pbrook/mbed,ban4jp/mbed,HeadsUpDisplayInc/mbed,Shengliang/mbed,DanKupiniak/mbed,pi19404/mbed,maximmbed/mbed,adustm/mbed,ARM-software/mbed-beetle,K4zuki/mbed,Tiryoh/mbed,geky/mbed,adustm/mbed,Sweet-Peas/mbed,getopenmono/mbed,mmorenobarm/mbed-os,alertby/mbed,mikaleppanen/mbed-os,Shengliang/mbed,pbrook/mbed,fvincenzo/mbed-os,alertby/mbed,mmorenobarm/mbed-os,tung7970/mbed-os-1,ban4jp/mbed,netzimme/mbed-os,JasonHow44/mbed,mnlipp/mbed,nabilbendafi/mbed,wodji/mbed,karsev/mbed-os,Marcomissyou/mbed,DanKupiniak/mbed,adustm/mbed,andreaslarssonublox/mbed,andreaslarssonublox/mbed,bcostm/mbed-os,pedromes/mbed,monkiineko/mbed-os,Marcomissyou/mbed,jferreir/mbed,Shengliang/mbed,j-greffe/mbed-os,struempelix/mbed,dbestm/mbed,jrjang/mbed,cvtsi2sd/mbed-os,Archcady/mbed-os,jpbrucker/mbed,RonEld/mbed,EmuxEvans/mbed,Sweet-Peas/mbed,masaohamanaka/mbed,radhika-raghavendran/mbed-os5.1-onsemi,nRFMesh/mbed-os,jeremybrodt/mbed,hwfwgrp/mbed,bentwire/mbed,GustavWi/mbed,getopenmono/mbed,CalSol/mbed,arostm/mbed-os,naves-thiago/mbed-midi,pradeep-gr/mbed-os5-onsemi,geky/mbed,mikaleppanen/mbed-os,nRFMesh/mbed-os,Shengliang/mbed,YarivCol/mbed-os,mikaleppanen/mbed-os,jferreir/mbed,nRFMesh/mbed-os,j-greffe/mbed-os,pradeep-gr/mbed-os5-onsemi,struempelix/mbed,kjbracey-arm/mbed,naves-thiago/mbed-midi,dbestm/mbed,mazimkhan/mbed-os,netzimme/mbed-os,getopenmono/mbed,struempelix/mbed,JasonHow44/mbed,ban4jp/mbed,fanghuaqi/mbed,hwfwgrp/mbed,pbrook/mbed,fahhem/mbed-os,svogl/mbed-os,mbedmicro/mbed,fahhem/mbed-os,andcor02/mbed-os,mazimkhan/mbed-os,JasonHow44/mbed,logost/mbed,j-greffe/mbed-os,screamerbg/mbed,nabilbendafi/mbed,fvincenzo/mbed-os,xcrespo/mbed,tung7970/mbed-os-1,svogl/mbed-os,bentwire/mbed,K4zuki/mbed,nRFMesh/mbed-os,maximmbed/mbed,kl-cruz/mbed-os,HeadsUpDisplayInc/mbed,jferreir/mbed,pradeep-gr/mbed-os5-onsemi,tung7970/mbed-os-1,fpiot/mbed-ats,mikaleppanen/mbed-os,CalSol/mbed,mazimkhan/mbed-os,bcostm/mbed-os,tung7970/mbed-os,mbedmicro/mbed,mbedmicro/mbed,nvlsianpu/mbed,NitinBhaskar/mbed,nabilbendafi/mbed,fpiot/mbed-ats,YarivCol/mbed-os,arostm/mbed-os,masaohamanaka/mbed,svogl/mbed-os,RonEld/mbed,radhika-raghavendran/mbed-os5.1-onsemi,andreaslarssonublox/mbed,masaohamanaka/mbed,jamesadevine/mbed,jpbrucker/mbed,bikeNomad/mbed,svogl/mbed-os,bulislaw/mbed-os,karsev/mbed-os,pedromes/mbed,Archcady/mbed-os,wodji/mbed,Timmmm/mbed,bulislaw/mbed-os,naves-thiago/mbed-midi,ban4jp/mbed,mbedmicro/mbed,monkiineko/mbed-os,Tiryoh/mbed,RonEld/mbed,kpurusho/mbed,kpurusho/mbed,naves-thiago/mbed-midi,CalSol/mbed,jrjang/mbed,infinnovation/mbed-os,jpbrucker/mbed,RonEld/mbed,bulislaw/mbed-os,j-greffe/mbed-os,jamesadevine/mbed,svastm/mbed,nRFMesh/mbed-os,al177/mbed,pi19404/mbed,screamerbg/mbed,kjbracey-arm/mbed,fvincenzo/mbed-os,fahhem/mbed-os,tung7970/mbed-os,hwfwgrp/mbed,adustm/mbed,jeremybrodt/mbed,mikaleppanen/mbed-os,mmorenobarm/mbed-os,rgrover/mbed,alertby/mbed,Timmmm/mbed,Sweet-Peas/mbed,theotherjimmy/mbed,jferreir/mbed,j-greffe/mbed-os,fahhem/mbed-os,mazimkhan/mbed-os,EmuxEvans/mbed,K4zuki/mbed,wodji/mbed,DanKupiniak/mbed,mnlipp/mbed,Marcomissyou/mbed,larks/mbed,cvtsi2sd/mbed-os,alertby/mbed,maximmbed/mbed,larks/mbed,wodji/mbed,jferreir/mbed,catiedev/mbed-os,HeadsUpDisplayInc/mbed,bulislaw/mbed-os,getopenmono/mbed,masaohamanaka/mbed,RonEld/mbed,rgrover/mbed,ban4jp/mbed,pbrook/mbed,andcor02/mbed-os,nvlsianpu/mbed,brstew/MBED-BUILD,fvincenzo/mbed-os,jrjang/mbed,bentwire/mbed,catiedev/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,dbestm/mbed,karsev/mbed-os,bulislaw/mbed-os,mikaleppanen/mbed-os,rosterloh/mbed,K4zuki/mbed,NitinBhaskar/mbed,ryankurte/mbed-os,Sweet-Peas/mbed,radhika-raghavendran/mbed-os5.1-onsemi,bentwire/mbed,ryankurte/mbed-os,betzw/mbed-os,xcrespo/mbed,larks/mbed,infinnovation/mbed-os,netzimme/mbed-os,mazimkhan/mbed-os,nvlsianpu/mbed,fpiot/mbed-ats,fanghuaqi/mbed,bentwire/mbed,nvlsianpu/mbed,Marcomissyou/mbed,karsev/mbed-os,kl-cruz/mbed-os,YarivCol/mbed-os,Archcady/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,EmuxEvans/mbed,GustavWi/mbed,Timmmm/mbed,pradeep-gr/mbed-os5-onsemi,bcostm/mbed-os,NXPmicro/mbed,pbrook/mbed,pi19404/mbed,theotherjimmy/mbed,tung7970/mbed-os,theotherjimmy/mbed,fanghuaqi/mbed,infinnovation/mbed-os,CalSol/mbed,svogl/mbed-os,maximmbed/mbed,maximmbed/mbed,NitinBhaskar/mbed,struempelix/mbed,theotherjimmy/mbed,getopenmono/mbed,fpiot/mbed-ats,monkiineko/mbed-os,mnlipp/mbed,geky/mbed,betzw/mbed-os,maximmbed/mbed,wodji/mbed,YarivCol/mbed-os,GustavWi/mbed,cvtsi2sd/mbed-os,theotherjimmy/mbed,Sweet-Peas/mbed,alertby/mbed,brstew/MBED-BUILD,fahhem/mbed-os,andreaslarssonublox/mbed,jrjang/mbed,jamesadevine/mbed,mazimkhan/mbed-os,nvlsianpu/mbed,bikeNomad/mbed,jamesadevine/mbed,logost/mbed,tung7970/mbed-os,Tiryoh/mbed,fvincenzo/mbed-os,kl-cruz/mbed-os,rosterloh/mbed,rgrover/mbed,struempelix/mbed,andcor02/mbed-os,infinnovation/mbed-os,brstew/MBED-BUILD,tung7970/mbed-os-1,autopulated/mbed,mmorenobarm/mbed-os,betzw/mbed-os,pedromes/mbed,NXPmicro/mbed,tung7970/mbed-os-1,hwfwgrp/mbed,devanlai/mbed,larks/mbed,pedromes/mbed,autopulated/mbed,DanKupiniak/mbed,geky/mbed,Shengliang/mbed,Archcady/mbed-os,svastm/mbed,screamerbg/mbed,Shengliang/mbed,kl-cruz/mbed-os,ryankurte/mbed-os,NXPmicro/mbed,jpbrucker/mbed,hwfwgrp/mbed,svastm/mbed,mmorenobarm/mbed-os,pradeep-gr/mbed-os5-onsemi,bikeNomad/mbed,infinnovation/mbed-os,pi19404/mbed,GustavWi/mbed,GustavWi/mbed,andcor02/mbed-os,jamesadevine/mbed,mnlipp/mbed,xcrespo/mbed,xcrespo/mbed,c1728p9/mbed-os,mnlipp/mbed,Sweet-Peas/mbed,jrjang/mbed,Tiryoh/mbed,fanghuaqi/mbed,netzimme/mbed-os,tung7970/mbed-os,kpurusho/mbed,monkiineko/mbed-os,wodji/mbed,dbestm/mbed,kpurusho/mbed,kl-cruz/mbed-os,c1728p9/mbed-os,masaohamanaka/mbed,arostm/mbed-os,brstew/MBED-BUILD,bulislaw/mbed-os,bcostm/mbed-os,brstew/MBED-BUILD,radhika-raghavendran/mbed-os5.1-onsemi,kjbracey-arm/mbed,karsev/mbed-os,jferreir/mbed,Timmmm/mbed,JasonHow44/mbed,fanghuaqi/mbed,mmorenobarm/mbed-os,screamerbg/mbed,devanlai/mbed,autopulated/mbed,logost/mbed