video: Migrate exynos display options to Kconfig

Following how it's done for the majority of drivers, add a new
VIDEO_EXYNOS option and Kconfig file under drivers/video/exynos and list
the current options there.

Cc: Anatolij Gustschin <agust@denx.de>
Cc: Jaehoon Chung <jh80.chung@samsung.com>
Cc: Minkyu Kang <mk7.kang@samsung.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Minkyu Kang <mk7.kang@samsung.com>
diff --git a/configs/spring_defconfig b/configs/spring_defconfig
index ad01756..366790b 100644
--- a/configs/spring_defconfig
+++ b/configs/spring_defconfig
@@ -95,6 +95,9 @@
 # CONFIG_VIDEO_BPP8 is not set
 CONFIG_VIDCONSOLE_AS_LCD=y
 CONFIG_DISPLAY=y
+CONFIG_VIDEO_EXYNOS=y
+CONFIG_EXYNOS_DP=y
+CONFIG_EXYNOS_FB=y
 CONFIG_VIDEO_BRIDGE=y
 CONFIG_VIDEO_BRIDGE_PARADE_PS862X=y
 CONFIG_LCD=y