arm: dts: imx8mp-beacon-kit: Enable USB Power domains

The USB Power domains should not have been removed as it causes
the board to hang if the USB is started.

Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Fabio Estevam <festevam@denx.de>

arch/arm/dts/imx8mp-beacon-kit-u-boot.dtsi

@@ -185,12 +185,10 @@
 
 &usb3_0 {
 	dma-ranges = <0x40000000 0x40000000 0xc0000000>;
-	/delete-property/ power-domains;
 };
 
 &usb3_1 {
 	dma-ranges = <0x40000000 0x40000000 0xc0000000>;
-	/delete-property/ power-domains;
 };
 
 &usb_dwc3_0 {