Critical section - fix for cortex-a
Critical section - fix for cortex-a

Cortex-A does not contain primask, there's 7th bit in the CPSR register,
that contains this information. Fixes #1851.

Renames primask variables to interrupts_disabled.

nRFMesh/mbed-os,NXPmicro/mbed,arostm/mbed-os,YarivCol/mbed-os,kjbracey-arm/mbed,jeremybrodt/mbed,andreaslarssonublox/mbed,screamerbg/mbed,bulislaw/mbed-os,mikaleppanen/mbed-os,theotherjimmy/mbed,svastm/mbed,svogl/mbed-os,ARM-software/mbed-beetle,catiedev/mbed-os,adamgreen/mbed,geky/mbed,andcor02/mbed-os,nvlsianpu/mbed,YarivCol/mbed-os,CalSol/mbed,arostm/mbed-os,CalSol/mbed,fvincenzo/mbed-os,svogl/mbed-os,nvlsianpu/mbed,kl-cruz/mbed-os,karsev/mbed-os,bulislaw/mbed-os,fanghuaqi/mbed,bcostm/mbed-os,nvlsianpu/mbed,netzimme/mbed-os,adustm/mbed,jeremybrodt/mbed,mbedmicro/mbed,fanghuaqi/mbed,adamgreen/mbed,bikeNomad/mbed,netzimme/mbed-os,Archcady/mbed-os,theotherjimmy/mbed,j-greffe/mbed-os,j-greffe/mbed-os,tung7970/mbed-os,betzw/mbed-os,NXPmicro/mbed,betzw/mbed-os,bikeNomad/mbed,Archcady/mbed-os,adamgreen/mbed,mazimkhan/mbed-os,kjbracey-arm/mbed,RonEld/mbed,RonEld/mbed,tung7970/mbed-os-1,ARM-software/mbed-beetle,infinnovation/mbed-os,mikaleppanen/mbed-os,maximmbed/mbed,theotherjimmy/mbed,mazimkhan/mbed-os,bcostm/mbed-os,NXPmicro/mbed,mmorenobarm/mbed-os,screamerbg/mbed,svogl/mbed-os,maximmbed/mbed,screamerbg/mbed,monkiineko/mbed-os,j-greffe/mbed-os,svogl/mbed-os,cvtsi2sd/mbed-os,theotherjimmy/mbed,andcor02/mbed-os,c1728p9/mbed-os,netzimme/mbed-os,kl-cruz/mbed-os,c1728p9/mbed-os,mmorenobarm/mbed-os,andcor02/mbed-os,tung7970/mbed-os,NXPmicro/mbed,mmorenobarm/mbed-os,mbedmicro/mbed,betzw/mbed-os,kl-cruz/mbed-os,mazimkhan/mbed-os,nRFMesh/mbed-os,rgrover/mbed,screamerbg/mbed,rgrover/mbed,fvincenzo/mbed-os,RonEld/mbed,maximmbed/mbed,HeadsUpDisplayInc/mbed,pradeep-gr/mbed-os5-onsemi,radhika-raghavendran/mbed-os5.1-onsemi,karsev/mbed-os,DanKupiniak/mbed,j-greffe/mbed-os,YarivCol/mbed-os,HeadsUpDisplayInc/mbed,mazimkhan/mbed-os,pradeep-gr/mbed-os5-onsemi,cvtsi2sd/mbed-os,betzw/mbed-os,ryankurte/mbed-os,monkiineko/mbed-os,adustm/mbed,kjbracey-arm/mbed,andreaslarssonublox/mbed,adustm/mbed,nvlsianpu/mbed,YarivCol/mbed-os,fanghuaqi/mbed,YarivCol/mbed-os,pradeep-gr/mbed-os5-onsemi,c1728p9/mbed-os,bulislaw/mbed-os,monkiineko/mbed-os,ryankurte/mbed-os,fvincenzo/mbed-os,DanKupiniak/mbed,tung7970/mbed-os,catiedev/mbed-os,geky/mbed,theotherjimmy/mbed,kl-cruz/mbed-os,cvtsi2sd/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,arostm/mbed-os,bcostm/mbed-os,arostm/mbed-os,RonEld/mbed,Archcady/mbed-os,bikeNomad/mbed,nRFMesh/mbed-os,jeremybrodt/mbed,NXPmicro/mbed,mmorenobarm/mbed-os,j-greffe/mbed-os,netzimme/mbed-os,tung7970/mbed-os-1,fvincenzo/mbed-os,pradeep-gr/mbed-os5-onsemi,monkiineko/mbed-os,Archcady/mbed-os,infinnovation/mbed-os,bikeNomad/mbed,andreaslarssonublox/mbed,fahhem/mbed-os,catiedev/mbed-os,bulislaw/mbed-os,ryankurte/mbed-os,CalSol/mbed,andcor02/mbed-os,rgrover/mbed,fanghuaqi/mbed,cvtsi2sd/mbed-os,infinnovation/mbed-os,svastm/mbed,fahhem/mbed-os,jeremybrodt/mbed,ARM-software/mbed-beetle,pradeep-gr/mbed-os5-onsemi,infinnovation/mbed-os,mikaleppanen/mbed-os,nRFMesh/mbed-os,c1728p9/mbed-os,mbedmicro/mbed,tung7970/mbed-os-1,rgrover/mbed,svastm/mbed,ryankurte/mbed-os,bikeNomad/mbed,mbedmicro/mbed,fanghuaqi/mbed,HeadsUpDisplayInc/mbed,HeadsUpDisplayInc/mbed,mikaleppanen/mbed-os,geky/mbed,rgrover/mbed,jeremybrodt/mbed,geky/mbed,svastm/mbed,kjbracey-arm/mbed,HeadsUpDisplayInc/mbed,netzimme/mbed-os,svogl/mbed-os,tung7970/mbed-os-1,nRFMesh/mbed-os,cvtsi2sd/mbed-os,nRFMesh/mbed-os,c1728p9/mbed-os,monkiineko/mbed-os,karsev/mbed-os,andcor02/mbed-os,HeadsUpDisplayInc/mbed,fahhem/mbed-os,karsev/mbed-os,nvlsianpu/mbed,radhika-raghavendran/mbed-os5.1-onsemi,bulislaw/mbed-os,infinnovation/mbed-os,catiedev/mbed-os,bcostm/mbed-os,catiedev/mbed-os,RonEld/mbed,Archcady/mbed-os,fahhem/mbed-os,mbedmicro/mbed,betzw/mbed-os,screamerbg/mbed,mazimkhan/mbed-os,bcostm/mbed-os,maximmbed/mbed,screamerbg/mbed,tung7970/mbed-os-1,andreaslarssonublox/mbed,mmorenobarm/mbed-os,infinnovation/mbed-os,CalSol/mbed,mazimkhan/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,tung7970/mbed-os,RonEld/mbed,adamgreen/mbed,kl-cruz/mbed-os,Archcady/mbed-os,maximmbed/mbed,NXPmicro/mbed,adustm/mbed,j-greffe/mbed-os,betzw/mbed-os,bcostm/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,nvlsianpu/mbed,arostm/mbed-os,CalSol/mbed,andreaslarssonublox/mbed,monkiineko/mbed-os,fvincenzo/mbed-os,adustm/mbed,svogl/mbed-os,andcor02/mbed-os,mikaleppanen/mbed-os,adustm/mbed,DanKupiniak/mbed,tung7970/mbed-os,fahhem/mbed-os,karsev/mbed-os,arostm/mbed-os,cvtsi2sd/mbed-os,YarivCol/mbed-os,geky/mbed,mikaleppanen/mbed-os,adamgreen/mbed,mmorenobarm/mbed-os,radhika-raghavendran/mbed-os5.1-onsemi,ryankurte/mbed-os,theotherjimmy/mbed,c1728p9/mbed-os,svastm/mbed,netzimme/mbed-os,kl-cruz/mbed-os,bulislaw/mbed-os,maximmbed/mbed,adamgreen/mbed,DanKupiniak/mbed,CalSol/mbed,pradeep-gr/mbed-os5-onsemi,ryankurte/mbed-os,fahhem/mbed-os,catiedev/mbed-os,karsev/mbed-os,ARM-software/mbed-beetle