[HAL] Ad primitives for long lived timestamp to the ticker API.
[HAL] Ad primitives for long lived timestamp to the ticker API.

- A new 64 timestamp type has been added: us_timestamp_t.
- Changed type of timestamp in ticker_events iinto us_timestamp_t.
- Event queue now have a to store a current, absolute timestamp.
- Add alternative versions of ticker_insert_event and ticker_read which accept
  in input us_timestamp_t.
- Add documentation explaining the limitation and behavior of ticker_read and
  ticker_insert_event.

bcostm/mbed-os,ryankurte/mbed-os,adamgreen/mbed,fahhem/mbed-os,c1728p9/mbed-os,c1728p9/mbed-os,screamerbg/mbed,infinnovation/mbed-os,bcostm/mbed-os,mazimkhan/mbed-os,mbedmicro/mbed,svogl/mbed-os,svogl/mbed-os,nRFMesh/mbed-os,andcor02/mbed-os,mbedmicro/mbed,CalSol/mbed,bcostm/mbed-os,ryankurte/mbed-os,catiedev/mbed-os,NXPmicro/mbed,betzw/mbed-os,catiedev/mbed-os,NXPmicro/mbed,mmorenobarm/mbed-os,fahhem/mbed-os,mmorenobarm/mbed-os,karsev/mbed-os,catiedev/mbed-os,monkiineko/mbed-os,svogl/mbed-os,bcostm/mbed-os,mazimkhan/mbed-os,NXPmicro/mbed,Archcady/mbed-os,mikaleppanen/mbed-os,Archcady/mbed-os,andcor02/mbed-os,catiedev/mbed-os,karsev/mbed-os,kjbracey-arm/mbed,mbedmicro/mbed,mazimkhan/mbed-os,adamgreen/mbed,adamgreen/mbed,nRFMesh/mbed-os,karsev/mbed-os,NXPmicro/mbed,screamerbg/mbed,infinnovation/mbed-os,bcostm/mbed-os,Archcady/mbed-os,adamgreen/mbed,pradeep-gr/mbed-os5-onsemi,monkiineko/mbed-os,HeadsUpDisplayInc/mbed,pradeep-gr/mbed-os5-onsemi,c1728p9/mbed-os,monkiineko/mbed-os,adamgreen/mbed,mikaleppanen/mbed-os,nRFMesh/mbed-os,andcor02/mbed-os,YarivCol/mbed-os,mazimkhan/mbed-os,karsev/mbed-os,fahhem/mbed-os,mbedmicro/mbed,HeadsUpDisplayInc/mbed,c1728p9/mbed-os,Archcady/mbed-os,NXPmicro/mbed,pradeep-gr/mbed-os5-onsemi,YarivCol/mbed-os,YarivCol/mbed-os,adamgreen/mbed,kjbracey-arm/mbed,betzw/mbed-os,betzw/mbed-os,screamerbg/mbed,monkiineko/mbed-os,fahhem/mbed-os,svogl/mbed-os,YarivCol/mbed-os,YarivCol/mbed-os,HeadsUpDisplayInc/mbed,Archcady/mbed-os,fahhem/mbed-os,infinnovation/mbed-os,karsev/mbed-os,CalSol/mbed,mmorenobarm/mbed-os,svogl/mbed-os,mazimkhan/mbed-os,karsev/mbed-os,andcor02/mbed-os,CalSol/mbed,NXPmicro/mbed,HeadsUpDisplayInc/mbed,infinnovation/mbed-os,ryankurte/mbed-os,catiedev/mbed-os,infinnovation/mbed-os,screamerbg/mbed,kjbracey-arm/mbed,betzw/mbed-os,infinnovation/mbed-os,mikaleppanen/mbed-os,mikaleppanen/mbed-os,HeadsUpDisplayInc/mbed,mazimkhan/mbed-os,fahhem/mbed-os,monkiineko/mbed-os,nRFMesh/mbed-os,andcor02/mbed-os,mikaleppanen/mbed-os,Archcady/mbed-os,mikaleppanen/mbed-os,mmorenobarm/mbed-os,screamerbg/mbed,c1728p9/mbed-os,ryankurte/mbed-os,betzw/mbed-os,CalSol/mbed,pradeep-gr/mbed-os5-onsemi,mmorenobarm/mbed-os,nRFMesh/mbed-os,nRFMesh/mbed-os,svogl/mbed-os,bcostm/mbed-os,mbedmicro/mbed,betzw/mbed-os,c1728p9/mbed-os,mmorenobarm/mbed-os,andcor02/mbed-os,ryankurte/mbed-os,pradeep-gr/mbed-os5-onsemi,CalSol/mbed,monkiineko/mbed-os,kjbracey-arm/mbed,catiedev/mbed-os,screamerbg/mbed,pradeep-gr/mbed-os5-onsemi,CalSol/mbed,YarivCol/mbed-os,HeadsUpDisplayInc/mbed,ryankurte/mbed-os