soc/amd/mendocino: Add support for separate RW A/B partition SPL file

Add support for having different Security Patch Level (SPL) table files
in the read-only and the read-write A/B partitions. This allows the SPL
table file in the main or RO FMAP partition to only cover the embedded
firmware binaries in that partition and have a separate SPL file in the
RW A and B partitions that covers the embedded firmware binaries in the
RW partitions.

BUG=b:243470283

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I1ba8c370ce14f7ec88e7ef2f9d0b64d6bb4fa176
Reviewed-on: https://review.coreboot.org/c/coreboot/+/67555
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martin.roth@amd.corp-partner.google.com>
diff --git a/src/soc/amd/mendocino/Kconfig b/src/soc/amd/mendocino/Kconfig
index 7155aab..d7c5372 100644
--- a/src/soc/amd/mendocino/Kconfig
+++ b/src/soc/amd/mendocino/Kconfig
@@ -421,6 +421,21 @@
 	depends on HAVE_SPL_FILE
 	default "3rdparty/blobs/mainboard/\$(CONFIG_MAINBOARD_DIR)/TypeId0x55_SplTableBl_MDN.sbin"
 
+config HAVE_SPL_RW_AB_FILE
+	bool "Have a separate mainboard-specific SPL file in RW A/B partitions"
+	default n
+	depends on HAVE_SPL_FILE
+	depends on VBOOT_SLOTS_RW_AB
+	help
+	  Have separate mainboard-specific Security Patch Level (SPL) table
+	  file for the RW A/B FMAP partitions. See the help text of
+	  HAVE_SPL_FILE for a more detailed description.
+
+config SPL_RW_AB_TABLE_FILE
+	string "Separate SPL table file for RW A/B partitions"
+	depends on HAVE_SPL_RW_AB_FILE
+	default "3rdparty/blobs/mainboard/\$(CONFIG_MAINBOARD_DIR)/TypeId0x55_SplTableBl_MDN.sbin"
+
 config PSP_SOFTFUSE_BITS
 	string "PSP Soft Fuse bits to enable"
 	default "34 28 6"