mb/facebook/monolith: Enable the xDCI controller

Enable the VBOOT_ALWAYS_ALLOW_UDC option to actually enable the xDCI
controller.

BUG=N/A
TEST=build

Change-Id: Ib51f2c82e69db83cebceb71ba5f1305764e0feca
Signed-off-by: Wim Vervoorn <wvervoorn@eltan.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38451
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Frans Hendriks <fhendriks@eltan.com>

src/mainboard/facebook/monolith/Kconfig

@@ -87,4 +87,8 @@ config VBOOT_ENABLE_CBFS_FALLBACK
 	default y
 	depends on VBOOT
 
+config VBOOT_ALWAYS_ALLOW_UDC
+	def_bool y
+	depends on VBOOT && !CHROMEOS
+
 endif