soc: microchip_mec: do not enable PM in soc

PM should not be enabled by default at the soc level. This is an
application decision and not a platform decision whether to enable or
disable PM features.

Enabling PM by default will result in descripencies and test scope and
failures in tests that do not account for PM being enabled.

Fixes #60359

Signed-off-by: Anas Nashif <anas.nashif@intel.com>