dt-bindings: usb: dwc2: Document quirk to reset PHY upon wakeup

On Rockchip rk3288 there's a hardware quirk where we need to assert
the reset signal to the PHY when we get a remote wakeup on one of the
two ports.  Document this quirk in the bindings.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

Documentation/devicetree/bindings/usb/dwc2.txt

@@ -42,6 +42,8 @@ Refer to phy/phy-bindings.txt for generic phy consumer properties
 - g-rx-fifo-size: size of rx fifo size in gadget mode.
 - g-np-tx-fifo-size: size of non-periodic tx fifo size in gadget mode.
 - g-tx-fifo-size: size of periodic tx fifo per endpoint (except ep0) in gadget mode.
+- snps,reset-phy-on-wake: If present indicates that we need to reset the PHY when
+                          we detect a wakeup.  This is due to a hardware errata.
 
 Deprecated properties:
 - g-use-dma: gadget DMA mode is automatically detected