video: make backlight and panel drivers optional

Not all boards use these drivers, so allow to disable them to fix
building boards with U-Boot binary image size restrictions.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index d0e9563..aaea7ce 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -14,9 +14,17 @@
 	  option compiles in the video uclass and routes all LCD/video access
 	  through this.
 
+config BACKLIGHT
+	bool "Enable panel backlight uclass support"
+	depends on DM_VIDEO
+	default y
+	help
+	  This provides backlight uclass driver that enables basic panel
+	  backlight support.
+
 config BACKLIGHT_PWM
 	bool "Generic PWM based Backlight Driver"
-	depends on DM_VIDEO && DM_PWM
+	depends on BACKLIGHT && DM_PWM
 	default y
 	help
 	  If you have a LCD backlight adjustable by PWM, say Y to enable
@@ -27,7 +35,7 @@
 
 config BACKLIGHT_GPIO
 	bool "Generic GPIO based Backlight Driver"
-	depends on DM_VIDEO
+	depends on BACKLIGHT
 	help
 	  If you have a LCD backlight adjustable by GPIO, say Y to enable
 	  this driver.
@@ -151,6 +159,21 @@
 	  loads takes over the screen.  This, for example, can be used to
 	  keep splash image on screen until grub graphical boot menu starts.
 
+config PANEL
+	bool "Enable panel uclass support"
+	depends on DM_VIDEO
+	default y
+	help
+	  This provides panel uclass driver that enables basic panel support.
+
+config SIMPLE_PANEL
+	bool "Enable simple panel support"
+	depends on PANEL
+	default y
+	help
+	  This turns on a simple panel driver that enables a compatible
+	  video panel.
+
 source "drivers/video/fonts/Kconfig"
 
 config VIDCONSOLE_AS_LCD