mb/google/dedede/var/sasuke: Add memory part and generate DRAM ID

This change adds memory part used by variant sasuke to
mem_part_used.txt and generates DRAM ID allocated to the part.

BUG=b:172104731

Change-Id: Ie8d66261cb5b4493afb1c677839f807bca994af5
Signed-off-by: Seunghwan Kim <sh_.kim@samsung.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48451
Reviewed-by: Raymond Chung <raymondchung@ami.corp-partner.google.com>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/dedede/variants/sasuke/memory/Makefile.inc

@@ -1,5 +1,5 @@
 ## SPDX-License-Identifier: GPL-2.0-or-later
 ## This is an auto-generated file. Do not edit!!
-## Add memory parts in mem_parts_used.txt and run spd_tools to regenerate.
 
-SPD_SOURCES = placeholder.spd.hex
+SPD_SOURCES =
+SPD_SOURCES += lp4x-spd-1.hex      # ID = 0(0b0000)  Parts = K4U6E3S4AA-MGCR

src/mainboard/google/dedede/variants/sasuke/memory/dram_id.generated.txt

@@ -1 +1,2 @@
 DRAM Part Name                 ID to assign
+K4U6E3S4AA-MGCR                0 (0000)

src/mainboard/google/dedede/variants/sasuke/memory/mem_parts_used.txt

@@ -1,6 +1 @@
-# This is a CSV file containing a list of memory parts used by this variant.
-# Generate an updated Makefile.inc and dram_id.generated.txt by running the
-# gen_part_id tool from util/spd_tools/lp4x
-# See util/spd_tools/lp4x/README.md for more details and instructions.
-
-# Part Name
+K4U6E3S4AA-MGCR