* Cortina Systems Gemini SATA Bridge

The Gemini SATA bridge in a SoC-internal PATA to SATA bridge that
takes two Faraday Technology FTIDE010 PATA controllers and bridges
them in different configurations to two SATA ports.

Required properties:
- compatible: should be
  "cortina,gemini-sata-bridge"
- reg: registers and size for the block
- resets: phandles to the reset lines for both SATA bridges
- reset-names: must be "sata0", "sata1"
- clocks: phandles to the compulsory peripheral clocks
- clock-names: must be "SATA0_PCLK", "SATA1_PCLK"
- syscon: a phandle to the global Gemini system controller
- cortina,gemini-ata-muxmode: tell the desired multiplexing mode for
  the ATA controller and SATA bridges. Values 0..3:
  Mode 0: ata0 master <-> sata0
          ata1 master <-> sata1
          ata0 slave interface brought out on IDE pads
  Mode 1: ata0 master <-> sata0
          ata1 master <-> sata1
          ata1 slave interface brought out on IDE pads
  Mode 2: ata1 master <-> sata1
          ata1 slave  <-> sata0
          ata0 master and slave interfaces brought out
               on IDE pads
  Mode 3: ata0 master <-> sata0
          ata0 slave  <-> sata1
          ata1 master and slave interfaces brought out
               on IDE pads

Optional boolean properties:
- cortina,gemini-enable-ide-pins: enables the PATA to IDE connection.
  The muxmode setting decides whether ATA0 or ATA1 is brought out,
  and whether master, slave or both interfaces get brought out.
- cortina,gemini-enable-sata-bridge: enables the PATA to SATA bridge
  inside the Gemnini SoC. The Muxmode decides what PATA blocks will
  be muxed out and how.

Example:

sata: sata@46000000 {
	compatible = "cortina,gemini-sata-bridge";
	reg = <0x46000000 0x100>;
	resets = <&rcon 26>, <&rcon 27>;
	reset-names = "sata0", "sata1";
	clocks = <&gcc GEMINI_CLK_GATE_SATA0>,
		 <&gcc GEMINI_CLK_GATE_SATA1>;
	clock-names = "SATA0_PCLK", "SATA1_PCLK";
	syscon = <&syscon>;
	cortina,gemini-ata-muxmode = <3>;
	cortina,gemini-enable-ide-pins;
	cortina,gemini-enable-sata-bridge;
};