* Freescale i.MX6 PCIe interface

This PCIe host controller is based on the Synopsis Designware PCIe IP
and thus inherits all the common properties defined in designware-pcie.txt.

Required properties:
- compatible: "fsl,imx6q-pcie", "fsl,imx6sx-pcie"
- reg: base address and length of the PCIe controller
- interrupts: A list of interrupt outputs of the controller. Must contain an
  entry for each entry in the interrupt-names property.
- interrupt-names: Must include the following entries:
	- "msi": The interrupt that is asserted when an MSI is received
- clock-names: Must include the following additional entries:
	- "pcie_phy"

Optional properties:
- fsl,tx-deemph-gen1: Gen1 De-emphasis value. Default: 0
- fsl,tx-deemph-gen2-3p5db: Gen2 (3.5db) De-emphasis value. Default: 0
- fsl,tx-deemph-gen2-6db: Gen2 (6db) De-emphasis value. Default: 20
- fsl,tx-swing-full: Gen2 TX SWING FULL value. Default: 127
- fsl,tx-swing-low: TX launch amplitude swing_low value. Default: 127

Additional required properties for imx6sx-pcie:
- clock names: Must include the following additional entries:
	- "pcie_inbound_axi"

Example:

	pcie@0x01000000 {
		compatible = "fsl,imx6q-pcie", "snps,dw-pcie";
		reg = <0x01ffc000 0x04000>,
		      <0x01f00000 0x80000>;
		reg-names = "dbi", "config";
		#address-cells = <3>;
		#size-cells = <2>;
		device_type = "pci";
		ranges = <0x00000800 0 0x01f00000 0x01f00000 0 0x00080000
			  0x81000000 0 0          0x01f80000 0 0x00010000
			  0x82000000 0 0x01000000 0x01000000 0 0x00f00000>;
		num-lanes = <1>;
		interrupts = <GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
		interrupt-names = "msi";
		#interrupt-cells = <1>;
		interrupt-map-mask = <0 0 0 0x7>;
		interrupt-map = <0 0 0 1 &intc GIC_SPI 123 IRQ_TYPE_LEVEL_HIGH>,
		                <0 0 0 2 &intc GIC_SPI 122 IRQ_TYPE_LEVEL_HIGH>,
		                <0 0 0 3 &intc GIC_SPI 121 IRQ_TYPE_LEVEL_HIGH>,
		                <0 0 0 4 &intc GIC_SPI 120 IRQ_TYPE_LEVEL_HIGH>;
		clocks = <&clks 144>, <&clks 206>, <&clks 189>;
		clock-names = "pcie", "pcie_bus", "pcie_phy";
	};