soc/intel: Fill DIMM serial number from SPD

Fill the DIMM serial number field for SMBIOS from the saved SPD
data that is returned by FSP.

BUG=b:132970635
TEST=This was tested on sarien to ensure that SMBIOS type 17
filled the serial number from the DIMM:

Handle 0x000B, DMI type 17, 40 bytes
Memory Device
        Locator: DIMM-A
        Serial Number: 41164beb

Change-Id: I85438bd1d581095ea3482dcf077a7f3389f1cd47
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32853
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>

src/soc/intel/apollolake/meminit_util_apl.c

@@ -90,6 +90,7 @@ void save_lpddr4_dimm_info_part_num(const char *dram_part_num)
 				src_dimm->DimmId,
 				dram_part_num,
 				strlen(dram_part_num),
+				NULL, /* SPD not available */
 				memory_info_hob->DataWidth);
 			index++;
 		}

src/soc/intel/apollolake/meminit_util_glk.c

@@ -96,6 +96,7 @@ void save_lpddr4_dimm_info_part_num(const char *dram_part_num)
 				    src_dimm->DimmId,
 				    dram_part_num,
 				    strlen(dram_part_num),
+				    src_dimm->SpdSave + SPD_SAVE_OFFSET_SERIAL,
 				    memory_info_hob->DataWidth);
 				index++;
 			}