boot: Imply CRC8 with VBE

VBE uses a crc8 checksum to verify that the nvdata is valid, so make
sure it is available if VBE is enabled.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/boot/Kconfig b/boot/Kconfig
index cdf787e..20935a2 100644
--- a/boot/Kconfig
+++ b/boot/Kconfig
@@ -704,6 +704,8 @@
 config BOOTMETH_VBE_SIMPLE
 	bool "Bootdev support for VBE 'simple' method"
 	default y
+	imply SPL_CRC8 if SPL
+	imply VPL_CRC8 if VPL
 	help
 	  Enables support for VBE 'simple' boot. This allows updating a single
 	  firmware image in boot media such as MMC. It does not support any sort