Convert CONFIG_VIDEO to Kconfig

This converts the following to Kconfig:
   CONFIG_VIDEO

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Jagan Teki <jteki@openedev.com>
diff --git a/configs/lwmon5_defconfig b/configs/lwmon5_defconfig
index b6a0bef..437b654 100644
--- a/configs/lwmon5_defconfig
+++ b/configs/lwmon5_defconfig
@@ -1,5 +1,6 @@
 CONFIG_PPC=y
 CONFIG_IDENT_STRING=" - v2.0"
+CONFIG_VIDEO=y
 CONFIG_4xx=y
 CONFIG_TARGET_LWMON5=y
 CONFIG_FIT=y