ARM: dts: at91: sama5d2: add sfrbu

SFRBU, the Special Function Registers Backup manage specific aspects of the
integrated memory, bridge implementations, processor and other
functionality not controlled elsewhere.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

Documentation/devicetree/bindings/arm/atmel-at91.txt

@@ -217,7 +217,8 @@ memory, bridge implementations, processor and other functionality not controlled
 elsewhere.
 
 required properties:
-- compatible: Should be "atmel,<chip>-sfr", "syscon".
+- compatible: Should be "atmel,<chip>-sfr", "syscon" or
+	"atmel,<chip>-sfrbu", "syscon"
   <chip> can be "sama5d3", "sama5d4" or "sama5d2".
 - reg: Should contain registers location and length
 

arch/arm/boot/dts/sama5d2.dtsi

@@ -1305,6 +1305,11 @@ AT91_XDMAC_DT_PERID(28))>,
 				status = "okay";
 			};
 
+			sfrbu: sfr@fc05c000 {
+				compatible = "atmel,sama5d2-sfrbu", "syscon";
+				reg = <0xfc05c000 0x20>;
+			};
+
 			chipid@fc069000 {
 				compatible = "atmel,sama5d2-chipid";
 				reg = <0xfc069000 0x8>;