Convert CONFIG_VIDEO_OMAP3 to Kconfig

This converts the following to Kconfig:
   CONFIG_VIDEO_OMAP3

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/configs/omap3_beagle_defconfig b/configs/omap3_beagle_defconfig
index 7709d2d..f26f5ad 100644
--- a/configs/omap3_beagle_defconfig
+++ b/configs/omap3_beagle_defconfig
@@ -75,6 +75,7 @@
 CONFIG_USB_ETHER_ASIX=y
 CONFIG_USB_ETHER_MCS7830=y
 CONFIG_USB_ETHER_SMSC95XX=y
+CONFIG_VIDEO_OMAP3=y
 CONFIG_FAT_WRITE=y
 CONFIG_BCH=y
 CONFIG_SPL_OF_LIBFDT=y