soc/intel: Drop pmc_soc_restore_power_failure()

Get rid of this function and its dangerous, weak implementation.
Instead, call pmc_set_power_failure_state() directly from the SMI
handler.

Change-Id: I0718afc5db66447c93289643f9097a4257b10934
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34727
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

src/soc/intel/skylake/pmc.c

@@ -68,11 +68,6 @@ void pmc_soc_set_afterg3_en(const bool on)
 	pci_write_config8(dev, GEN_PMCON_B, reg8);
 }
 
-void pmc_soc_restore_power_failure(void)
-{
-	pmc_set_power_failure_state(false);
-}
-
 #if ENV_RAMSTAGE
 /* Fill up PMC resource structure */
 int pmc_soc_get_resources(struct pmc_resource_config *cfg)