include/memory_info.h: Add soc_num to dimm_info struct

Sometimes, server platforms may have more than one socket on server
board. However, there's no field to store information about which
socket the DIMM comes from in dimm_info structure.

This patch adds soc_num field in dimm_info structure to store socket
ID of the DIMM.

Signed-off-by: Tim Chu <Tim.Chu@quantatw.com>
Change-Id: I1b9e2b87fda2d7c32ecb8ce9d989795c8b869cea
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70662
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jonathan Zhang <jonzhang@fb.com>
Reviewed-by: Marc Jones <marc@marcjonesconsulting.com>

src/include/memory_info.h

@@ -33,6 +33,10 @@ struct dimm_info {
 	 */
 	uint16_t ddr_frequency;
 	uint8_t rank_per_dimm;
+	/*
+	 * Socket-ID
+	 */
+	uint8_t soc_num;
 	/*
 	 * Memory-Controller-ID
 	 */