mb/google/rex: Create karis4es variant

This patch creates a new variant karis4es.

The new variant will support only ESx samples. The existing karis
variant will support the QS samples.

BUG=b:293326312
TEST=Image built properly

Change-Id: I854fee7206528a235f027ff8ec98593a02be4806
Signed-off-by: Eran Mitrani <mitrani@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/76761
Reviewed-by: Subrata Banik <subratabanik@google.com>
Reviewed-by: Tyler Wang <tyler.wang@quanta.corp-partner.google.com>
Reviewed-by: YH Lin <yueherngl@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>

src/mainboard/google/rex/Kconfig

@@ -61,6 +61,10 @@ config BOARD_GOOGLE_MODEL_SCREEBO
 	select DRIVERS_GENERIC_ALC1015
 	select DRIVERS_GENESYSLOGIC_GL9750
 
+config BOARD_GOOGLE_MODEL_KARIS
+	def_bool n
+	select BOARD_GOOGLE_BASEBOARD_REX
+
 config BOARD_GOOGLE_BASEBOARD_OVIS
 	def_bool n
 	select BOARD_GOOGLE_REX_COMMON
@@ -127,6 +131,7 @@ config MAINBOARD_PART_NUMBER
 	default "Screebo" if BOARD_GOOGLE_SCREEBO
 	default "Screebo4ES" if BOARD_GOOGLE_SCREEBO4ES
 	default "Karis" if BOARD_GOOGLE_KARIS
+	default "Karis4ES" if BOARD_GOOGLE_KARIS4ES
 	default "Ovis" if BOARD_GOOGLE_OVIS
 	default "Ovis4ES" if BOARD_GOOGLE_OVIS4ES
 
@@ -134,7 +139,7 @@ config VARIANT_DIR
 	string
 	default "rex0" if BOARD_GOOGLE_MODEL_REX
 	default "screebo" if BOARD_GOOGLE_MODEL_SCREEBO
-	default "karis" if BOARD_GOOGLE_KARIS
+	default "karis" if BOARD_GOOGLE_MODEL_KARIS
 	default "ovis" if BOARD_GOOGLE_MODEL_OVIS
 
 config DIMM_SPD_SIZE

src/mainboard/google/rex/Kconfig.name

@@ -14,7 +14,11 @@ config BOARD_GOOGLE_SCREEBO4ES
 
 config BOARD_GOOGLE_KARIS
 	bool "->  Karis"
-	select BOARD_GOOGLE_BASEBOARD_REX
+	select BOARD_GOOGLE_MODEL_KARIS
+
+config BOARD_GOOGLE_KARIS4ES
+	bool "->  Karis4ES"
+	select BOARD_GOOGLE_MODEL_KARIS
 
 config BOARD_GOOGLE_REX_EC_ISH
 	bool "-> Rex EC ISH"