[PATCH v2 3/3] usb: dwc3: add debugfs node to dump FIFO/Queue available space

From: "Du, Changbin" For DWC3 USB controller, the Global Debug Queue/FIFO Space Available Register(GDBGFIFOSPACE) can be used to dump FIFO/Queue available space. This can be used to check some special issues, like whether data is successfully copied from memory to fifo

[PATCH v2 3/3] usb: dwc3: add debugfs node to dump FIFO/Queue available space

From: "Du, Changbin" For DWC3 USB controller, the Global Debug Queue/FIFO Space Available Register(GDBGFIFOSPACE) can be used to dump FIFO/Queue available space. This can be used to check some special issues, like whether data is successfully copied from memory to fifo when a trb is blocked.