Device-Tree bindings for framebuffer hdmi driver

Required properties:
- compatible: 	Should be "fsl,sii902x".
- reg: 		The I2C address of the device.
- interrupts:	Interrupt number to the cpu.

Example:

&i2c1 {
       status = "okay";
       hdmi: sii9022a@39 {
             compatible = "fsl,sii902x";
             reg = <0x39>;
             interrupts = <GIC_SPI 167 IRQ_TYPE_EDGE_RISING>;
       };
};
