ARM i.MX53: Add IOMUXC GPR to device tree

Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx53.dtsi

@@ -515,6 +515,11 @@ MX53_PAD_KEY_ROW1__UART5_RXD_MUX 0x1c5
 
 			};
 
+			gpr: iomuxc-gpr@53fa8000 {
+				compatible = "fsl,imx53-iomuxc-gpr", "syscon";
+				reg = <0x53fa8000 0xc>;
+			};
+
 			pwm1: pwm@53fb4000 {
 				#pwm-cells = <2>;
 				compatible = "fsl,imx53-pwm", "fsl,imx27-pwm";