* Altera Arria10 System Control IC

Required parent device properties:
- compatible : "altr,a10sycon"
- spi-max-frequency : Maximum SPI frequency.
- reg : the SPI Chip Select address for the Arria10 System Controller chip
- interrupts : IRQ line for the Arria10 System Controller chip
- interrupt-controller: describes the Arria10 System Controller as an
  interrupt controller  (has its own domain)
- interrupt-parent: The GPIO line that is used for key interrupts.
- #interrupt-cells : should be 2.

The A10SyCon consists of this varied group of sub-devices:

Device			 Supply Names	 Description
------			 ------------	 -----------
a10sycon-gpio		:		: GPIO Controller
a10sycon-hwmon		:		: Hardware Monitor
a10sycon-reset		:		: Reset Manager

The input key and LEDs are implemented entirely in the device tree using
the gpio-leds and gpio-keys frameworks.

Example:

        a10_sysctl: a10_sysctl@0 {
		compatible = "altr,a10sycon";
		reg = <0>;
		interrupt-parent = <&gpio1>;
		/* low-level active IRQ at GPIO1_5 */
		interrupts = <5 0x8>;
		interrupt-controller;
		#interrupt-cells = <2>;
		spi-max-frequency = <100000>;

		gpio4: gpio-controller {
			compatible = "altr,a10sycon-gpio";
			gpio-controller;
			#gpio-cells = <2>;
			ngpios = <16>;
		};

		hwmon: a10hwmon {
			compatible = "altr,a10sycon-hwmon";
		};

		a10rst: a10rst {
			compatible = "altr,a10sycon-reset";
			#reset-cells = <1>;
		};
	};
