Altera FPGAs in passive serial mode
-----------------------------------

This binding defines the control interface to Altera FPGAs in
passive serial mode. This is used to upload the firmware and
to start the FPGA.

Required properties:
- compatible: shall be "altr,fpga-passive-serial" or
  "altr,fpga-arria10-passive-serial" for Arria 10
- reg: SPI chip select
- nstat-gpios: Specify GPIO for controlling the nstat pin
- confd-gpios: Specify GPIO for controlling the confd pin
- nconfig-gpios: Specify GPIO for controlling the nconfig pin

Example:

	fpga@0 {
		compatible = "altr,fpga-passive-serial";
		nstat-gpios = <&gpio4 18 0>;
		confd-gpios = <&gpio4 19 0>;
		nconfig-gpios = <&gpio4 20 0>;
		spi-max-frequency = <10000000>;
		reg = <0>;
	};