* Amlogic Meson AO-CEC driver

The Amlogic Meson AO-CEC module is present is Amlogic SoCs and its purpose is
to handle communication between HDMI connected devices over the CEC bus.

Required properties:
  - compatible : value should be following depending on the SoC :
	For GXBB, GXL, GXM, G12A and SM1 (AO_CEC_A module) :
	"amlogic,meson-gx-ao-cec"
	For G12A (AO_CEC_B module) :
	"amlogic,meson-g12a-ao-cec"
	For SM1 (AO_CEC_B module) :
	"amlogic,meson-sm1-ao-cec"

  - reg : Physical base address of the IP registers and length of memory
	  mapped region.

  - interrupts : AO-CEC interrupt number to the CPU.
  - clocks : from common clock binding: handle to AO-CEC clock.
  - clock-names : from common clock binding, must contain :
		For GXBB, GXL, GXM, G12A and SM1 (AO_CEC_A module) :
		- "core"
		For G12A, SM1 (AO_CEC_B module) :
		- "oscin"
		corresponding to entry in the clocks property.
  - hdmi-phandle: phandle to the HDMI controller

Example:

cec_AO: cec@100 {
	compatible = "amlogic,meson-gx-ao-cec";
	reg = <0x0 0x00100 0x0 0x14>;
	interrupts = <GIC_SPI 199 IRQ_TYPE_EDGE_RISING>;
	clocks = <&clkc_AO CLKID_AO_CEC_32K>;
	clock-names = "core";
	hdmi-phandle = <&hdmi_tx>;
};