modules: cmsis: Move cortex_m default configuration to its own file

Kconfig parameters, header’s default & silicon vendor’s SDK configuration
for CMSIS Core, must be consistent. Depending on the inclusion order of
the headers, this is currently not always the case.

This change introduces consistency checks & enusers defaults match their
Kconfig settings.

Signed-off-by: Wilfried Chauveau <wilfried.chauveau@arm.com>