usb: dwc3: Check for ESS TX/RX threshold config

Check and configure TX/RX threshold for DWC_usb31. Update dwc3 structure
with new fields to store these threshold configurations.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>