soc/amd/picasso: fix MCACHE on psp_verstage RO boot

On RW boot path psp_verstage call cbfs_map which calls chain of
_cbfs_alloc, cbfs_boot_lookup and cbfs_get_boot_device. Then
cbfs_get_boot_device initializes MCACHE which is used later.

However on RO boot path psp_verstage doesn't try to find anything in the
CBFS which results RO MCACHE not to be initialized. Add
cbfs_get_boot_device(true) to explicitly initialize MCACHE on recovery
boot.

BUG=b:177091575
BRANCH=none
TEST=build and boot jelboz

Signed-off-by: Kangheui Won <khwon@chromium.org>
Change-Id: I6c4b522fef5a4affd215faa122bdf6b53190cf3d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/54711
Reviewed-by: Julius Werner <jwerner@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/soc/amd/common/psp_verstage/psp_verstage.c b/src/soc/amd/common/psp_verstage/psp_verstage.c
index 2265e17..5c59c4f 100644
--- a/src/soc/amd/common/psp_verstage/psp_verstage.c
+++ b/src/soc/amd/common/psp_verstage/psp_verstage.c
@@ -238,6 +238,16 @@
 		reboot_into_recovery(ctx, retval);
 
 	post_code(POSTCODE_UPDATE_BOOT_REGION);
+
+	/*
+	 * Since psp_verstage doesn't load next stage we never call
+	 * any cbfs API on RO path. However we still need to initialize
+	 * RO CBFS MCACHE manually to pass it in transfer_buffer.
+	 * In RW path, MCACHE build will be skipped for RO region since
+	 * we already built here.
+	 */
+	cbfs_get_boot_device(true);
+
 	retval = update_boot_region(ctx);
 	if (retval)
 		reboot_into_recovery(ctx, retval);