mb/intel/mtlrvp: Add CPU power limit values

Add support of variant_devtree_update() function to override
devtree settings for variant boards. Also, add CPU power limit
values for mtlrvp baseboard.

BRANCH=None
BUG=None
TEST=Built the changes

Change-Id: I11bc17f25d4880562d016e29f81e37e068bb6757
Signed-off-by: Sumeet Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75730
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/intel/mtlrvp/Kconfig

@@ -17,6 +17,7 @@ config BOARD_INTEL_MTLRVP_COMMON
 	select HAVE_ACPI_TABLES
 	select HAVE_SPD_IN_CBFS
 	select MAINBOARD_HAS_CHROMEOS
+	select SOC_INTEL_COMMON_BLOCK_VARIANT_POWER_LIMIT
 	select SOC_INTEL_CSE_LITE_SKU
 	select SOC_INTEL_METEORLAKE_U_P