mb/google/volteer/var/terrador: Add memory parts and generate DRAM IDs

This change adds memory parts used by variant terrador to
mem_list_variant.txt and generates DRAM IDs allocated to these parts.

Added memory
1. MT53E512M64D4NW-046 WT:E
2. MT53E1G64D8NW-046 WT:E

BUG=b:159195585,b:152936481,b:156435028
TEST="emerge-volteer coreboot chromeos-bootimage", flash terrador and
verify terrador boots to kernel.

Signed-off-by: David Wu <david_wu@quanta.corp-partner.google.com>
Change-Id: Ia14f76e9cb0df64961d46f4b61b39439e56f6a8c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41995
Reviewed-by: Zhuohao Lee <zhuohao@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Nick Vaccaro <nvaccaro@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/volteer/variants/terrador/Makefile.inc

@@ -1,7 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
 
-SPD_SOURCES =
-
 bootblock-y += gpio.c
 
 romstage-y += memory.c

src/mainboard/google/volteer/variants/terrador/memory/Makefile.inc

@@ -0,0 +1,6 @@
+## SPDX-License-Identifier: GPL-2.0-or-later
+## This is an auto-generated file. Do not edit!!
+
+SPD_SOURCES =
+SPD_SOURCES += spd-1.hex      # ID = 0(0b0000)  Parts = MT53E512M64D4NW-046 WT:E
+SPD_SOURCES += spd-3.hex      # ID = 1(0b0001)  Parts = MT53E1G64D8NW-046 WT:E

src/mainboard/google/volteer/variants/terrador/memory/dram_id.generated.txt

@@ -0,0 +1,3 @@
+DRAM Part Name                 ID to assign
+MT53E512M64D4NW-046 WT:E       0 (0000)
+MT53E1G64D8NW-046 WT:E         1 (0001)

src/mainboard/google/volteer/variants/terrador/memory/mem_list_variant.txt

@@ -0,0 +1,2 @@
+MT53E512M64D4NW-046 WT:E
+MT53E1G64D8NW-046 WT:E