bindings: Add DT bindings for video

* Qualcomm Technologies Inc MSM VIDC VMEM

Required properties:

- compatible : "qcom,msm-vmem"

- interrupts : Contains the interrupt that maps to the VMEM module

- reg : A set of 2 start address and size pairs that describe the hardware

register address space and mappable memory address space.

- reg-names : Strings that describe the pairs in "reg".  The register address

space should be called "reg-base" and the memory space should be called "mem-base".

- clocks : A set of clocks that correspond to the AHB and MAXI clocks that the

hardware uses.

- clock-names : A string that describes the "clocks" property.  The AHB clock

should be named "ahb" and the MAXI clock should be named "maxi".

- qcom,bank-size : The size of each memory bank, in bytes.

- vdd-supply: phandle to a regulator that is considered to be the footswitch for vmem.

- qcom,msm-bus,(name|num-cases,num-paths,vectors-KBps) - Bus to be voted for prior to

  issuing any IO transactions to vmem.  Refer to Documentation/devicetree/bindings/arm/\

  msm/msm_bus_adhoc.txt for further details.

Example:

qcom,vmem@880000 {

	compatible = "qcom,msm-vmem";

	interrupts = <0 429 0>;

	reg = <0x880000 0x800>,

	    <0x6800000 0x100000>;

	reg-names = "reg-base", "mem-base";

	vdd-supply = <&gdsc_mmagic_video>;

	clocks = <&clock_mmss clk_vmem_ahb_clk>,

	       <&clock_mmss clk_vmem_maxi_clk>;

	clock-names = "ahb", "maxi";

	qcom,bank-size = <131072>;

	qcom,msm-bus,name = "vmem";

	qcom,msm-bus,num-cases = <2>;

	qcom,msm-bus,num-paths = <1>;

	qcom,msm-bus,vectors-KBps =

	        <MSM_BUS_MASTER_AMPSS_M0 MSM_BUS_SLAVE_VMEM_CFG   0   0>,

	        <MSM_BUS_MASTER_AMPSS_M0 MSM_BUS_SLAVE_VMEM_CFG 500 800>;

};