Convert CONFIG_IMX_VIDEO_SKIP et al to Kconfig

This converts the following to Kconfig:
   CONFIG_IMX_VIDEO_SKIP
   CONFIG_IMX_HDMI

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/pico-imx6_defconfig b/configs/pico-imx6_defconfig
index 9b3f76d..a6ed013 100644
--- a/configs/pico-imx6_defconfig
+++ b/configs/pico-imx6_defconfig
@@ -99,6 +99,8 @@
 CONFIG_SYS_WHITE_ON_BLACK=y
 # CONFIG_PANEL is not set
 CONFIG_VIDEO_IPUV3=y
+CONFIG_IMX_VIDEO_SKIP=y
+CONFIG_IMX_HDMI=y
 CONFIG_SPLASH_SCREEN=y
 CONFIG_SPLASH_SCREEN_ALIGN=y
 CONFIG_BMP_16BPP=y