Binding for TI DP159 programmable i2c retimer

Reference
[1] DP159 Data Sheet
	http://www.ti.com/lit/ds/symlink/sn65dp159.pdf

The SNx5DP159 device is a dual mode DisplayPort to transition-minimized
differential signal (TMDS) retimer supporting digital video interface
(DVI) 1.0 and high-definition multimedia interface (HDMI) 1.4b and 2.0
output signals. The internal structure of the retimer can be found in [1].

==I2C device node==

Required properties:
- compatible: shall be "ti,dp159".
- status: shall be "okay"
- reg: i2c device address, shall be 0x5e.
- #clock-cells: from common clock binding; shall be set to 0.
- #address-cells: shall be set to 1.
- #size-cells: shall be set to 0.

==Example==

	dp159: hdmi-retimer@5e {
		status = "okay";
		compatible = "ti,dp159";
		reg = <0x5e>;
		#address-cells = <1>;
		#size-cells = <0>;
		#clock-cells = <0>;
	};			
