DWC_usb31 controller has a different UsbRxPktCnt bit fields from
GRXTHRCFG register. Check for DWC_usb31 IP revision to read the
appropriate value.
Signed-off-by: NThinh Nguyen <thinhn@synopsys.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>