Revert "arch: arm: cortex_m: pm_s2ram: Rework S2RAM mark functions"

What is the change?
 - This reverts commit 474d4c32

Why do we need this change?
 - This commit was added because Cortex-M didn't have a valid
   stack to make required functionality work however,
   the previous commit fixes this and makes interrupt stack
   available for use. This removes Arm specific limitation from
   these generic APIs so revert the commit to reflect the same.

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