QCOM BAM DMA controller

Required properties:
- compatible: must contain "qcom,bam-v1.4.0" for MSM8974
- reg: Address range for DMA registers
- interrupts: Should contain the one interrupt shared by all channels
- #dma-cells: must be <1>, the cell in the dmas property of the client device
  represents the channel number
- clocks: required clock
- clock-names: must contain "bam_clk" entry
- qcom,ee : indicates the active Execution Environment identifier (0-7) used in
  the secure world.

Example:

	uart-bam: dma@f9984000 = {
		compatible = "qcom,bam-v1.4.0";
		reg = <0xf9984000 0x15000>;
		interrupts = <0 94 0>;
		clocks = <&gcc GCC_BAM_DMA_AHB_CLK>;
		clock-names = "bam_clk";
		#dma-cells = <1>;
		qcom,ee = <0>;
	};

DMA clients must use the format described in the dma.txt file, using a two cell
specifier for each channel.

Example:
	serial@f991e000 {
		compatible = "qcom,msm-uart";
		reg = <0xf991e000 0x1000>
			<0xf9944000 0x19000>;
		interrupts = <0 108 0>;
		clocks = <&gcc GCC_BLSP1_UART2_APPS_CLK>,
			<&gcc GCC_BLSP1_AHB_CLK>;
		clock-names = "core", "iface";

		dmas = <&uart-bam 0>, <&uart-bam 1>;
		dma-names = "rx", "tx";
	};