* CSR SiRFSoC DMA controller

See dma.txt first

Required properties:
- compatible: Should be "sirf,prima2-dmac" or "sirf,marco-dmac"
- reg: Should contain DMA registers location and length.
- interrupts: Should contain one interrupt shared by all channel
- #dma-cells: must be <1>. used to represent the number of integer
    cells in the dmas property of client device.
- clocks: clock required

Example:

Controller:
dmac0: dma-controller@b00b0000 {
	compatible = "sirf,prima2-dmac";
	reg = <0xb00b0000 0x10000>;
	interrupts = <12>;
	clocks = <&clks 24>;
	#dma-cells = <1>;
};


Client:
Fill the specific dma request line in dmas. In the below example, spi0 read
channel request line is 9 of the 2nd dma controller, while write channel uses
4 of the 2nd dma controller; spi1 read channel request line is 12 of the 1st
dma controller, while write channel uses 13 of the 1st dma controller:

spi0: spi@b00d0000 {
	compatible = "sirf,prima2-spi";
	dmas = <&dmac1 9>,
		<&dmac1 4>;
	dma-names = "rx", "tx";
};

spi1: spi@b0170000 {
	compatible = "sirf,prima2-spi";
	dmas = <&dmac0 12>,
		<&dmac0 13>;
	dma-names = "rx", "tx";
};