ARM: dts: sam9x60: add rtt

Add RTT. Allong with it enable GBPR as it is requested by RTT.

Signed-off-by: Claudiu Beznea <[e-mail]>
Signed-off-by: Alexandre Belloni <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]

arch/arm/boot/dts/at91-sam9x60ek.dts

···
 	};
 };
 
+&gpbr {
+	status = "okay";
+};
+
 &i2s {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_i2s_default>;
···
 			reg = <0x200000 0x600000>;
 		};
 	};
+};
+
+&rtt {
+	atmel,rtt-rtc-time-reg = <&gpbr 0x0>;
+	status = "okay";
 };
 
 &shutdown_controller {

arch/arm/boot/dts/sam9x60.dtsi

···
 				status = "disabled";
 			};
 
+			rtt: rtt@fffffe20 {
+				compatible = "microchip,sam9x60-rtt", "atmel,at91sam9260-rtt";
+				reg = <0xfffffe20 0x20>;
+				interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
+				clocks = <&clk32k 0>;
+			};
+
 			pit: timer@fffffe40 {
 				compatible = "atmel,at91sam9260-pit";
 				reg = <0xfffffe40 0x10>;