soc/amd/picasso: Disable CBFS MCACHE

This is causing boot errors on zork:

coreboot-v1.9308_26_0.0.22-18590-g4598a7bed945 Wed Dec 16 17:32:25 UTC 2020 bootblock starting (log level: 8)...
Family_Model: 00820f01
PSP boot mode: Development
Silicon level: Pre-Production
PMxC0 STATUS: 0x800 BIT11
I2C bus 3 version 0x3132322a
DW I2C bus 3 at 0xfedc5000 (400 KHz)
FMAP: area FW_MAIN_B found @ 312000 (3137280 bytes)
ASSERTION ERROR: file 'src/commonlib/bsd/cbfs_mcache.c', line 106

BUG=b:177323348
TEST=Boot ezkinil to OS

Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I1f2bbdd9c87c4efdfb0042e90a20b489fa0efced
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49128
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
diff --git a/src/soc/amd/picasso/Kconfig b/src/soc/amd/picasso/Kconfig
index bd36822..5c682db 100644
--- a/src/soc/amd/picasso/Kconfig
+++ b/src/soc/amd/picasso/Kconfig
@@ -58,6 +58,7 @@
 	select UDK_2017_BINDING
 	select HAVE_CF9_RESET
 	select SUPPORT_CPU_UCODE_IN_CBFS
+	select NO_CBFS_MCACHE if VBOOT_STARTS_BEFORE_BOOTBLOCK
 
 config FSP_M_FILE
 	string "FSP-M (memory init) binary path and filename"