arch: arm: set interrupt stack protection with MSPLIM

This commit implements the build-in interrupt stack protection
via the native MSPLIM register in ARMv8-M MCUs that support the
Main Extension. Main stack pointer overflows will cause Stack
Overflow UsageFaults. In addition, the commit introduces a new
config option, BUILTIN_STACK_GUARD, allowing the user to enable
and use the built-in stack protection in ARMv8-M firmware.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>