arch: arm: update to use CMSIS_6 compatible macros

Zephyr switched to using CMSIS_6 module in f726cb51
which breaks certain boards like `nucleo_h745zi_q/stm32h745xx/m7` when
CONFIG_CORTEX_M_DWT, CONFIG_TIMING_FUNCTIONS are enabled and cmsis from
`module/hal/cmsis` is not available (deleted explicitly after west
update).

This commit adds a provision to be able to use CMSIS_6 macros when the
module cmsis is not available.

Signed-off-by: Sudan Landge <sudan.landge@arm.com>