usb: host: add Kconfig for USB_XHCI_ROCKCHIP

Add a Kconfig for Rockchip xhci controller.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Acked-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 42e8a9f..61e13d7 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -21,6 +21,13 @@
 	  Say Y or if your system has a Dual Role SuperSpeed
 	  USB controller based on the DesignWare USB3 IP Core.
 
+config USB_XHCI_ROCKCHIP
+	bool "Support for Rockchip on-chip xHCI USB controller"
+	depends on ARCH_ROCKCHIP
+	default y
+	help
+	  Enables support for the on-chip xHCI controller on Rockchip SoCs.
+
 endif # USB_XHCI_HCD
 
 config USB_EHCI_HCD