usb: dwc3: add UniPhier specific glue layer

Add UniPhier platform specific glue layer to support USB3 Host mode
on Synopsys DWC3 IP.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index a291ceb..ae7fc1c 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -37,6 +37,13 @@
 
 	  Say 'Y' here if you have one such device
 
+config USB_DWC3_UNIPHIER
+	bool "DesignWare USB3 Host Support on UniPhier Platforms"
+	depends on ARCH_UNIPHIER && USB_XHCI_DWC3
+	help
+	  Support of USB2/3 functionality in Socionext UniPhier platforms.
+	  Say 'Y' here if you have one such device.
+
 menu "PHY Subsystem"
 
 config USB_DWC3_PHY_OMAP