soc/amd/common/block/apob/apob_cache.c: Add assert for APOB DRAM size

Add static check to ensure the reserved APOB DRAM space is the same size
as the MRC_CACHE region specified in the fmap.

Update sabrina APOB DRAM size to match the fmap.

TEST: Timeless builds identical. Test build with a larger MRC_CACHE than
APOB DRAM failed the assert as expected.

Signed-off-by: Fred Reitberger <reitbergerfred@gmail.com>
Change-Id: Ia14f6ef94b9062df0612fe96098b1012085ccf9c
Reviewed-on: https://review.coreboot.org/c/coreboot/+/65878
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/amd/sabrina/Kconfig b/src/soc/amd/sabrina/Kconfig
index 62ae598..997a1be 100644
--- a/src/soc/amd/sabrina/Kconfig
+++ b/src/soc/amd/sabrina/Kconfig
@@ -125,11 +125,11 @@
 
 config PSP_APOB_DRAM_SIZE
 	hex
-	default 0x20000
+	default 0x1E000
 
 config PSP_SHAREDMEM_BASE
 	hex
-	default 0x2021000 if VBOOT
+	default 0x201F000 if VBOOT
 	default 0x0
 	help
 	  This variable defines the base address in DRAM memory where PSP copies