mb/lenovo/{x200,t400}: Add VBOOT support

Tested on thinkpad X200 with CONFIG_H8_FN_KEY_AS_VBOOT_RECOVERY_SW
selected, the RW_A slot is properly selected unless the FN button is
pressed. 600+ms are spend waiting for the EC to be ready.

Change-Id: I689fe310e5b828f2e68fcbe9afd582f35738ed1d
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35998
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/lenovo/t400/Kconfig b/src/mainboard/lenovo/t400/Kconfig
index 2caf1d3..8d286c4 100644
--- a/src/mainboard/lenovo/t400/Kconfig
+++ b/src/mainboard/lenovo/t400/Kconfig
@@ -28,6 +28,24 @@
 	select MAINBOARD_USES_IFD_GBE_REGION if !BOARD_LENOVO_R500
 	select INTEL_GMA_HAVE_VBT
 
+config VBOOT
+	select VBOOT_VBNV_CMOS
+	select GBB_FLAG_DISABLE_LID_SHUTDOWN
+	select GBB_FLAG_DISABLE_PD_SOFTWARE_SYNC
+	select GBB_FLAG_DISABLE_EC_SOFTWARE_SYNC
+	select GBB_FLAG_DISABLE_FWMP
+
+config VBOOT_SLOTS_RW_A
+	default y
+
+config VBOOT_VBNV_OFFSET
+	hex
+	default 0x82
+
+config FMDFILE
+	string
+	default "src/mainboard/$(CONFIG_MAINBOARD_DIR)/vboot-rwa.fmd" if VBOOT
+
 config MAINBOARD_DIR
 	string
 	default lenovo/t400