Altera FPGA/HPS Bridge Driver

Required properties:
- regs		: base address and size for AXI bridge module
- compatible	: Should contain one of:
		  "altr,socfpga-lwhps2fpga-bridge",
		  "altr,socfpga-hps2fpga-bridge", or
		  "altr,socfpga-fpga2hps-bridge"
- resets	: Phandle and reset specifier for this bridge's reset
- clocks	: Clocks used by this module.

Optional properties:
- bridge-enable	: 0 if driver should disable bridge at startup.
		  1 if driver should enable bridge at startup.
		  Default is to leave bridge in its current state.

Example:
	fpga_bridge0: fpga-bridge@ff400000 {
		compatible = "altr,socfpga-lwhps2fpga-bridge";
		reg = <0xff400000 0x100000>;
		resets = <&rst LWHPS2FPGA_RESET>;
		clocks = <&l4_main_clk>;
		bridge-enable = <0>;
	};

	fpga_bridge1: fpga-bridge@ff500000 {
		compatible = "altr,socfpga-hps2fpga-bridge";
		reg = <0xff500000 0x10000>;
		resets = <&rst HPS2FPGA_RESET>;
		clocks = <&l4_main_clk>;
		bridge-enable = <1>;
	};

	fpga_bridge2: fpga-bridge@ff600000 {
		compatible = "altr,socfpga-fpga2hps-bridge";
		reg = <0xff600000 0x100000>;
		resets = <&rst FPGA2HPS_RESET>;
		clocks = <&l4_main_clk>;
	};