ARM: digicolor: enable CX92755 on-chip RTC device

Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/boot/dts/cx92755.dtsi

@@ -82,6 +82,12 @@ timer@f0000fc0 {
 		clocks = <&main_clk>;
 	};
 
+	rtc@f0000c30 {
+		compatible = "cnxt,cx92755-rtc";
+		reg = <0xf0000c30 0x18>;
+		interrupts = <25>;
+	};
+
 	uc_regs: syscon@f00003a0 {
 		compatible = "cnxt,cx92755-uc", "syscon";
 		reg = <0xf00003a0 0x10>;