soc/amd/picasso: fix CBFS MCACHE on Zork

Zork platform was not booting with MCACHE enabled since psp_verstage
had following issues with MCACHE.
Fix all the issues and re-enable MCACHE for Zork.

* psp_verstage should call vboot_run_logic, not verstage_main.
vboot_run_logic calls after_verstage which handles RW MCACHE build.

* It should avoid low-level apis for cbfs access.
cbfs_map will build RO MCACHE if it's the first stage, while other
low-level apis won't.

* It should call update_boot_region before save_buffers
MCACHE should be transferred to x86 so we should build it before
calling save_buffers

BUG=b:177323348
BRANCH=none
TEST=boot Ezkinil

Signed-off-by: Kangheui Won <khwon@chromium.org>
Change-Id: I08c5f8474600a06e3a08358733a38f70787e944a
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49468
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/amd/picasso/Kconfig

@@ -59,7 +59,6 @@ config CPU_SPECIFIC_OPTIONS
 	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"