ARM: dts: imx25: Fix PWM "per" clocks

Currently PWM functionality is broken on mx25 due to the wrong assignment of the
PWM "per" clock.

According to Documentation/devicetree/bindings/clock/imx25-clock.txt:
	pwm_ipg_per		52

,so update the pwm "per" to use 'pwm_ipg_per' instead of 'per10' clock.

With this change PWM can work fine on mx25.

Cc: <stable@vger.kernel.org>
Reported-by: Carlos Soto <csotoalonso@gmail.com>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx25.dtsi

@@ -369,7 +369,7 @@ pwm2: pwm@53fa0000 {
 				compatible = "fsl,imx25-pwm", "fsl,imx27-pwm";
 				#pwm-cells = <2>;
 				reg = <0x53fa0000 0x4000>;
-				clocks = <&clks 106>, <&clks 36>;
+				clocks = <&clks 106>, <&clks 52>;
 				clock-names = "ipg", "per";
 				interrupts = <36>;
 			};
@@ -388,7 +388,7 @@ pwm3: pwm@53fa8000 {
 				compatible = "fsl,imx25-pwm", "fsl,imx27-pwm";
 				#pwm-cells = <2>;
 				reg = <0x53fa8000 0x4000>;
-				clocks = <&clks 107>, <&clks 36>;
+				clocks = <&clks 107>, <&clks 52>;
 				clock-names = "ipg", "per";
 				interrupts = <41>;
 			};
@@ -429,7 +429,7 @@ slcdc@53fc0000 {
 			pwm4: pwm@53fc8000 {
 				compatible = "fsl,imx25-pwm", "fsl,imx27-pwm";
 				reg = <0x53fc8000 0x4000>;
-				clocks = <&clks 108>, <&clks 36>;
+				clocks = <&clks 108>, <&clks 52>;
 				clock-names = "ipg", "per";
 				interrupts = <42>;
 			};
@@ -476,7 +476,7 @@ pwm1: pwm@53fe0000 {
 				compatible = "fsl,imx25-pwm", "fsl,imx27-pwm";
 				#pwm-cells = <2>;
 				reg = <0x53fe0000 0x4000>;
-				clocks = <&clks 105>, <&clks 36>;
+				clocks = <&clks 105>, <&clks 52>;
 				clock-names = "ipg", "per";
 				interrupts = <26>;
 			};