vboot: Separate vboot from chromeos

VBOOT_VERIFY_FIRMWARE should be independent of CHROMEOS. This allows use
of verified boot library without having to stick to CHROMEOS.

BUG=chrome-os-partner:55639

Change-Id: Ia2c328712caedd230ab295b8a613e3c1ed1532d9
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/15867
Tested-by: build bot (Jenkins)
Reviewed-by: Duncan Laurie <dlaurie@chromium.org>
diff --git a/src/mainboard/google/gru/Kconfig b/src/mainboard/google/gru/Kconfig
index 0b061af..1b657d9 100644
--- a/src/mainboard/google/gru/Kconfig
+++ b/src/mainboard/google/gru/Kconfig
@@ -39,9 +39,9 @@
 	select SPI_FLASH_WINBOND
 
 config CHROMEOS
-	select CHROMEOS_VBNV_FLASH
 	select EC_SOFTWARE_SYNC
 	select SPI_TPM
+	select VBOOT_VBNV_FLASH
 	select VIRTUAL_DEV_SWITCH
 
 config MAINBOARD_DIR