* AT91 SAMA5D2 Analog to Digital Converter (ADC)

Required properties:
  - compatible: Should be "atmel,sama5d2-adc".
  - reg: Should contain ADC registers location and length.
  - interrupts: Should contain the IRQ line for the ADC.
  - clocks: phandle to device clock.
  - clock-names: Must be "adc_clk".
  - vref-supply: Supply used as reference for conversions.
  - vddana-supply: Supply for the adc device.
  - atmel,min-sample-rate-hz: Minimum sampling rate, it depends on SoC.
  - atmel,max-sample-rate-hz: Maximum sampling rate, it depends on SoC.
  - atmel,startup-time-ms: Startup time expressed in ms, it depends on SoC.

Example:

adc: adc@fc030000 {
	compatible = "atmel,sama5d2-adc";
	reg = <0xfc030000 0x100>;
	interrupts = <40 IRQ_TYPE_LEVEL_HIGH 7>;
	clocks = <&adc_clk>;
	clock-names = "adc_clk";
	atmel,min-sample-rate-hz = <200000>;
	atmel,max-sample-rate-hz = <20000000>;
	atmel,startup-time-ms = <4>;
	vddana-supply = <&vdd_3v3_lp_reg>;
	vref-supply = <&vdd_3v3_lp_reg>;
}