ARM: dts: imx6qdl: add necessary thermal clk

Thermal sensor needs pll3_usb_otg when measuring temperature,
so we need to pass clk info to thermal driver.
Signed-off-by: NAnson Huang <b20788@freescale.com>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx6qdl.dtsi

@@ -568,6 +568,7 @@
 				interrupts = <0 49 IRQ_TYPE_LEVEL_HIGH>;
 				fsl,tempmon = <&anatop>;
 				fsl,tempmon-data = <&ocotp>;
+				clocks = <&clks 172>;
 			};
 
 			usbphy1: usbphy@020c9000 {