Qualcomm CI13xxx (Chipidea) USB controllers

Required properties:
- compatible:   should contain "qcom,ci-hdrc"
- reg:          offset and length of the register set in the memory map
- interrupts:   interrupt-specifier for the controller interrupt.
- usb-phy:      phandle for the PHY device
- dr_mode:      Should be "peripheral"

Examples:
	gadget@f9a55000 {
		compatible = "qcom,ci-hdrc";
		reg = <0xf9a55000 0x400>;
		dr_mode = "peripheral";
		interrupts = <0 134 0>;
		usb-phy = <&usbphy0>;
	};