ARM: dts: sun6i: Add missing timers interrupts

The timer unit in the A31 has 6 interrupts available. List all of them.
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>

arch/arm/boot/dts/sun6i-a31.dtsi

@@ -736,7 +736,8 @@ timer@1c20c00 {
 				     <GIC_SPI 19 IRQ_TYPE_LEVEL_HIGH>,
 				     <GIC_SPI 20 IRQ_TYPE_LEVEL_HIGH>,
 				     <GIC_SPI 21 IRQ_TYPE_LEVEL_HIGH>,
-				     <GIC_SPI 22 IRQ_TYPE_LEVEL_HIGH>;
+				     <GIC_SPI 22 IRQ_TYPE_LEVEL_HIGH>,
+				     <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
 			clocks = <&osc24M>;
 		};