soc/intel/alderlake: Call into PMC IPC to inform PCI enumeration done

This patch calls into the PMC IPC function that informs about PMC
enumeration.

Note: Alder Lake FSP Notify Phase 1 callback missed to send this PMC
IPC, hence, this patch is considered as an improvement over FSP Notify
Phase API.

BUG=b:211954778
TEST=Able to build and boot google/redrix to OS without any PMC IPC
error.

Signed-off-by: Subrata Banik <subratabanik@google.com>
Change-Id: I43cfad25a5861c5aa5dae293ff42c9cefe862ea2
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63954
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Lean Sheng Tan <sheng.tan@9elements.com>

src/soc/intel/alderlake/lockdown.c

@@ -9,6 +9,7 @@
 #include <device/mmio.h>
 #include <intelblocks/cfg.h>
 #include <intelblocks/pcr.h>
+#include <intelblocks/pmclib.h>
 #include <intelpch/lockdown.h>
 #include <soc/pcr_ids.h>
 #include <soc/pm.h>
@@ -36,6 +37,9 @@ static void pmc_lockdown_cfg(int chipset_lockdown)
 		setbits32(pmcbase + PM_CFG, PM_CFG_DBG_MODE_LOCK |
 					 PM_CFG_XRAM_READ_DISABLE);
 	}
+
+	/* Send PMC IPC to inform about PCI enumeration done */
+	pmc_send_pci_enum_done();
 }
 
 static void pch_lockdown_cfg(void)