usb: dwc2: do not gate off the hardware if it does not support clock gating

usb: dwc2: do not gate off the hardware if it does not support clock gating

We should not be clearing the HCD_FLAG_HW_ACCESSIBLE bit if the hardware
does not support clock gating.

Fixes: 50fb0c128b6e ("usb: dwc2: Add clock gating entering flow by system suspend")
Acked-by: Minas Harutyunyan <Minas.Harutyunyan@synopsys.com>
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>
Link: https://lore.kernel.org/r/20220104135922.734776-1-dinguyen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>