ARM: dts: at91: sama5d3_xplained: fix ADC vref

commit 9cdd31e5 upstream.

The voltage reference for the ADC is not 3V but 3.3V since it is connected to
VDDANA.
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

arch/arm/boot/dts/at91-sama5d3_xplained.dts

@@ -141,6 +141,7 @@ spi1: spi@f8008000 {
 			};
 
 			adc0: adc@f8018000 {
+				atmel,adc-vref = <3300>;
 				pinctrl-0 = <
 					&pinctrl_adc0_adtrg
 					&pinctrl_adc0_ad0