usb: dwc2: eliminate irq parameter from dwc2_hcd_init

The irq is available in hsotg already, so there's no need to
pass it as separate function parameter.

Acked-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>