Ilitek ILI9322 TFT panel driver with SPI control bus

This is a driver for 320x240 TFT panels, accepting a variety of input
streams that get adapted and scaled to the panel. The panel output has
960 TFT source driver pins and 240 TFT gate driver pins, VCOM, VCOML and
VCOMH outputs.

Required properties:
  - compatible: "dlink,dir-685-panel", "ilitek,ili9322"
    (full system-specific compatible is always required to look up configuration)
  - reg: address of the panel on the SPI bus

Optional properties:
  - vcc-supply: core voltage supply, see regulator/regulator.txt
  - iovcc-supply: voltage supply for the interface input/output signals,
    see regulator/regulator.txt
  - vci-supply: voltage supply for analog parts, see regulator/regulator.txt
  - reset-gpios: a GPIO spec for the reset pin, see gpio/gpio.txt

  The following optional properties only apply to RGB and YUV input modes and
  can be omitted for BT.656 input modes:

  - pixelclk-active: see display/panel/display-timing.txt
  - de-active: see display/panel/display-timing.txt
  - hsync-active: see display/panel/display-timing.txt
  - vsync-active: see display/panel/display-timing.txt

The panel must obey the rules for a SPI slave device as specified in
spi/spi-bus.txt

The device node can contain one 'port' child node with one child
'endpoint' node, according to the bindings defined in
media/video-interfaces.txt. This node should describe panel's video bus.

Example:

panel: display@0 {
	compatible = "dlink,dir-685-panel", "ilitek,ili9322";
	reg = <0>;
	vcc-supply = <&vdisp>;
	iovcc-supply = <&vdisp>;
	vci-supply = <&vdisp>;

	port {
		panel_in: endpoint {
			remote-endpoint = <&display_out>;
		};
	};
};