Doxygen: Added cross-reference from RTX5 hardware requirements to CMSIS-Core(A) IRQ Controller API.
Doxygen: Added cross-reference from RTX5 hardware requirements to CMSIS-Core(A) IRQ Controller API.

Change-Id: Idfd75a33b2c60bfaa6d91877fdd44b7a092f7f35

JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,JonatanAntoni/CMSIS_5,ARM-software/CMSIS_5,ARM-software/CMSIS_5,ARM-software/CMSIS_5,ARM-software/CMSIS_5,JonatanAntoni/CMSIS_5,ARM-software/CMSIS_5,JonatanAntoni/CMSIS_5,ARM-software/CMSIS_5