usb: dwc2: gadget: Remove duplicated phy init

The function dwc2_hsotg_init is only called once just before calling
dwc2_hsotg_core_init_disconnected which does the same initialization:
setting the usbcfg register with turnaround time, timeout calibration
and phy width.

Acked-by: Minas Harutyunyan <hminas@synopsys.com>
Signed-off-by: Jules Maselbas <jmaselbas@kalray.eu>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>