dt-bindings: usb: dwc3: Update dwc3 TX fifo properties

dt-bindings: usb: dwc3: Update dwc3 TX fifo properties

Update the tx-fifo-resize property with a better description, while
adding the tx-fifo-max-num, which is a new parameter allowing
adjustments for the maximum number of packets the txfifo resizing logic
can account for while resizing the endpoints.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1625908395-5498-7-git-send-email-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>