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/mx7dsabresd_defconfig b/configs/mx7dsabresd_defconfig
index 3203551..efe85cd 100644
--- a/configs/mx7dsabresd_defconfig
+++ b/configs/mx7dsabresd_defconfig
@@ -4,6 +4,7 @@
 # CONFIG_ARMV7_VIRT is not set
 CONFIG_IMX_RDC=y
 CONFIG_IMX_BOOTAUX=y
+CONFIG_VIDEO=y
 CONFIG_SYS_EXTRA_OPTIONS="IMX_CONFIG=board/freescale/mx7dsabresd/imximage.cfg"
 CONFIG_BOOTDELAY=3
 CONFIG_HUSH_PARSER=y