usb: dwc3: qcom: fix missing optional irq warnings

usb: dwc3: qcom: fix missing optional irq warnings

Not all platforms have all of the four currently supported wakeup
interrupts so use the optional irq helpers when looking up interrupts to
avoid printing error messages when an optional interrupt is not found:

	dwc3-qcom a6f8800.usb: error -ENXIO: IRQ hs_phy_irq not found

Fixes: a4333c3a6ba9 ("usb: dwc3: Add Qualcomm DWC3 glue driver")
Reviewed-by: Andrew Halaney <ahalaney@redhat.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20220713131340.29401-4-johan+linaro@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>