ARM: dts: at91: sama5d4: fix pinctrl compatible string

The compatible string is incorrect. Add atmel,sama5d3-pinctrl since
it's the appropriate compatible string. Remove the
atmel,at91rm9200-pinctrl compatible string, this fallback is
useless, there are too many changes.
Signed-off-by: Santiago Esteban <Santiago.Esteban@microchip.com>
Signed-off-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: stable@vger.kernel.org #v3.18
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

arch/arm/boot/dts/sama5d4.dtsi

@@ -1379,7 +1379,7 @@ dbgu: serial@fc069000 {
 			pinctrl@fc06a000 {
 				#address-cells = <1>;
 				#size-cells = <1>;
-				compatible = "atmel,at91sam9x5-pinctrl", "atmel,at91rm9200-pinctrl", "simple-bus";
+				compatible = "atmel,sama5d3-pinctrl", "atmel,at91sam9x5-pinctrl", "simple-bus";
 				ranges = <0xfc068000 0xfc068000 0x100
 					  0xfc06a000 0xfc06a000 0x4000>;
 				/* WARNING: revisit as pin spec has changed */