Device-Tree bindings for tilcdc DRM generic panel output driver

Required properties:
 - compatible: value should be "ti,tilcdc,panel".
 - panel-info: configuration info to configure LCDC correctly for the panel
   - ac-bias: AC Bias Pin Frequency
   - ac-bias-intrpt: AC Bias Pin Transitions per Interrupt
   - dma-burst-sz: DMA burst size
   - bpp: Bits per pixel
   - fdd: FIFO DMA Request Delay
   - sync-edge: Horizontal and Vertical Sync Edge: 0=rising 1=falling
   - sync-ctrl: Horizontal and Vertical Sync: Control: 0=ignore
   - raster-order: Raster Data Order Select: 1=Most-to-least 0=Least-to-most
   - fifo-th: DMA FIFO threshold
 - display-timings: typical videomode of lcd panel.  Multiple video modes
   can be listed if the panel supports multiple timings, but the 'native-mode'
   should be the preferred/default resolution.  Refer to
   Documentation/devicetree/bindings/video/display-timing.txt for display
   timing binding details.

Optional properties:
- backlight: phandle of the backlight device attached to the panel
- enable-gpios: GPIO pin to enable or disable the panel

Recommended properties:
 - pinctrl-names, pinctrl-0: the pincontrol settings to configure
   muxing properly for pins that connect to TFP410 device

Example:

	/* Settings for CDTech_S035Q01 / LCD3 cape: */
	lcd3 {
		compatible = "ti,tilcdc,panel";
		pinctrl-names = "default";
		pinctrl-0 = <&bone_lcd3_cape_lcd_pins>;
		backlight = <&backlight>;
		enable-gpios = <&gpio3 19 0>;

		panel-info {
			ac-bias           = <255>;
			ac-bias-intrpt    = <0>;
			dma-burst-sz      = <16>;
			bpp               = <16>;
			fdd               = <0x80>;
			sync-edge         = <0>;
			sync-ctrl         = <1>;
			raster-order      = <0>;
			fifo-th           = <0>;
		};
		display-timings {
			native-mode = <&timing0>;
			timing0: 320x240 {
				hactive         = <320>;
				vactive         = <240>;
				hback-porch     = <21>;
				hfront-porch    = <58>;
				hsync-len       = <47>;
				vback-porch     = <11>;
				vfront-porch    = <23>;
				vsync-len       = <2>;
				clock-frequency = <8000000>;
				hsync-active    = <0>;
				vsync-active    = <0>;
			};
		};
	};