ARM: ux500: Configure the PRCMU Timer for db8500 based devices in DT

This patch adds the information required for successful
registration of the PRCMU timer 4 (clocksource) driver to the
db8500 Device Tree include file.
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

arch/arm/boot/dts/db8500.dtsi

@@ -171,7 +171,13 @@ prcmu@80157000 {
 			reg = <0x80157000 0x1000>;
 			interrupts = <46 47>;
 			#address-cells = <1>;
-			#size-cells = <0>;
+			#size-cells = <1>;
+			ranges;
+
+				prcmu-timer-4@80157450 {
+				compatible = "stericsson,db8500-prcmu-timer-4";
+				reg = <0x80157450 0xC>;
+			};
 
 			ab8500@5 {
 				compatible = "stericsson,ab8500";