ext: hal: cmsis: Update ARM CMSIS headers to version 5.6.0

Origin: ARM CMSIS v5.6.0
License: Apache-2.0
URL: https://github.com/ARM-software/CMSIS_5.git


commit: b5f0603d6a584d1724d952fd8b0737458b90d62b
Purpose: CMSIS Headers update.
Maintained-by: External

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>