* Altera PCIe controller

Required properties:
- compatible :	should contain "altr,pcie-root-port-1.0"
- reg:		a list of physical base address and length for TXS and CRA.
- reg-names:	must include the following entries:
		"Txs": TX slave port region
		"Cra": Control register access region
- interrupt-parent:	interrupt source phandle.
- interrupts:	specifies the interrupt source of the parent interrupt
		controller.  The format of the interrupt specifier depends
		on the parent interrupt controller.
- device_type:	must be "pci"
- #address-cells:	set to <3>
- #size-cells:		set to <2>
- #interrupt-cells:	set to <1>
- ranges:	describes the translation of addresses for root ports and
		standard PCI regions.
- interrupt-map-mask and interrupt-map: standard PCI properties to define the
		mapping of the PCIe interface to interrupt numbers.

Optional properties:
- msi-parent:	Link to the hardware entity that serves as the MSI controller
		for this PCIe controller.
- bus-range:	PCI bus numbers covered

Example
	pcie_0: pcie@0xc00000000 {
		compatible = "altr,pcie-root-port-1.0";
		reg = <0xc0000000 0x20000000>,
			<0xff220000 0x00004000>;
		reg-names = "Txs", "Cra";
		interrupt-parent = <&hps_0_arm_gic_0>;
		interrupts = <0 40 4>;
		interrupt-controller;
		#interrupt-cells = <1>;
		bus-range = <0x0 0xFF>;
		device_type = "pci";
		msi-parent = <&msi_to_gic_gen_0>;
		#address-cells = <3>;
		#size-cells = <2>;
		interrupt-map-mask = <0 0 0 7>;
		interrupt-map = <0 0 0 1 &pcie_0 1>,
			            <0 0 0 2 &pcie_0 2>,
			            <0 0 0 3 &pcie_0 3>,
			            <0 0 0 4 &pcie_0 4>;
		ranges = <0x82000000 0x00000000 0x00000000 0xc0000000 0x00000000 0x10000000
			  0x82000000 0x00000000 0x10000000 0xd0000000 0x00000000 0x10000000>;
	};
