usb: xhci-dwc3: Add support for dis_u2_susphy_quirk

This quirk is necessary for the Amlogic GXL SoCs otherwise the
Port 2 PHY doesn't get out of suspend and U-Boot resets the board after:

XHCI timeout on event type 33... cannot recover.
BUG: failure at drivers/usb/host/xhci-ring.c:474/xhci_wait_for_event()!
BUG!

This quirk is also handled in the dwc3 core code, but until the
xhci-dwc3 driver uses the dwc3 core, the quirk must be handled here
to fix USB support on the Amlogic libretech-cc and libretech-ac board
when a device is only plugged in the OTG port.

Cc: Yuri Frolov <crashing.kernel@gmail.com>
Cc: Bin Meng <bmeng.cn@gmail.com>
Fixes: dc9cdf859e ("usb: dwc3: Add DWC3 controller driver support")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/drivers/usb/host/xhci-dwc3.c b/drivers/usb/host/xhci-dwc3.c
index 9e8cae7..55a1b22 100644
--- a/drivers/usb/host/xhci-dwc3.c
+++ b/drivers/usb/host/xhci-dwc3.c
@@ -150,6 +150,9 @@
 	if (dev_read_bool(dev, "snps,dis-u2-freeclk-exists-quirk"))
 		reg &= ~DWC3_GUSB2PHYCFG_U2_FREECLK_EXISTS;
 
+	if (dev_read_bool(dev, "snps,dis_u2_susphy_quirk"))
+		reg &= ~DWC3_GUSB2PHYCFG_SUSPHY;
+
 	writel(reg, &dwc3_reg->g_usb2phycfg[0]);
 
 	dr_mode = usb_get_dr_mode(dev_of_offset(dev));