soc/intel/common: Implement power-failure-state handling

This is a consolidation of the respective feature in `soc/intel/*lake/`,
including additional support for MAINBOARD_POWER_STATE_PREVIOUS.

For the latter, firmware has to keep track of the `previous` state. The
feature was already advertised in Kconfig long ago, but not implemented.

SoC code has to call pmc_set_power_failure_state() at least once during
boot and needs to implement pmc_soc_set_afterg3_en() for the actual
register write.

Change-Id: Ic6970a79d9b95373c2855f4c92232d2aa05963bb
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34724
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

0 files changed, 0 insertions, 0 deletions