arm64: dts: sprd: Add one suspend timer

On Spreadtrum platform, the current clocksource for timekeeping will be
stopped in suspend state, thus add one always-on timer to calculate the
suspend time.
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>

arch/arm64/boot/dts/sprd/whale2.dtsi

@@ -146,6 +146,12 @@ timer@40050000 {
 				clocks = <&ext_32k>;
 			};
 
+			timer@40050020 {
+				compatible = "sprd,sc9860-suspend-timer";
+				reg = <0 0x40050020 0 0x20>;
+				clocks = <&ext_32k>;
+			};
+
 			hwlock: hwspinlock@40500000 {
 				compatible = "sprd,hwspinlock-r3p0";
 				reg = <0 0x40500000 0 0x1000>;