soc/intel/skylake: Add function to clear PMCON status bits

This patch adds an SoC function to clear GEN_PMCON_A status bits to
align with other IA coreboot implementations.

Additionally, move the PMCON status bit clear operation to finalize.c
to cover any such chances where FSP-S NotifyPhase requested a global
reset and PMCON status bit remains set.

BUG=b:211954778
TEST=None.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: Ie786e6ba2daf88accb5d70be33de0abe593f8c53
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61650
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>
diff --git a/src/soc/intel/skylake/finalize.c b/src/soc/intel/skylake/finalize.c
index 5021595..afa1c02 100644
--- a/src/soc/intel/skylake/finalize.c
+++ b/src/soc/intel/skylake/finalize.c
@@ -65,6 +65,8 @@
 
 	/* Hide p2sb device as the OS must not change BAR0. */
 	p2sb_hide();
+
+	pmc_clear_pmcon_sts();
 }
 
 static void soc_lockdown(struct device *dev)