ARM: at91: sama5d4: Add SFR

The sama4d4 has Special Function Registers that allow to manage DDR, OHCI, EBI
and AIC interrupt redirection.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com>
[nicolas.ferre@atmel.com: reg size: 0x60]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

arch/arm/boot/dts/sama5d4.dtsi

@@ -870,6 +870,11 @@ i2c2: i2c@f8024000 {
 				status = "disabled";
 			};
 
+			sfr: sfr@f8028000 {
+				compatible = "atmel,sama5d4-sfr", "syscon";
+				reg = <0xf8028000 0x60>;
+			};
+
 			mmc1: mmc@fc000000 {
 				compatible = "atmel,hsmci";
 				reg = <0xfc000000 0x600>;