chromeos: Provide watchdog support in verstage

Some boards may want to initialize watchdog in verstage instead of
bootblock or ramstage, so we need to add watchdog support in verstage.

BRANCH=none
BUG=b:120588396
TEST=build successfully

Change-Id: I13ab84f54d576a0e8c723070b5d9aadd9d63f87c
Signed-off-by: You-Cheng Syu <youcheng@google.com>
Reviewed-on: https://review.coreboot.org/c/30329
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>

src/vendorcode/google/chromeos/Makefile.inc

@@ -24,5 +24,6 @@ ramstage-$(CONFIG_USE_SAR) += sar.c
 ramstage-$(CONFIG_TPM_CR50) += cr50_enable_update.c
 ifeq ($(CONFIG_ARCH_MIPS),)
 bootblock-y += watchdog.c
+verstage-y += watchdog.c
 ramstage-y += watchdog.c
 endif