usb: Add MediaTek USB3 DRD driver

This patch adds support for the MediaTek USB3 controller
integrated into MT8173. It currently supports High-Speed
Peripheral Only mode.

Super-Speed Peripheral, Dual-Role Device and Host Only (xHCI)
modes will be added in the next patchs.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_USB_DWC2)		+= dwc2/
 obj-$(CONFIG_USB_ISP1760)	+= isp1760/
 
 obj-$(CONFIG_USB_MON)		+= mon/
+obj-$(CONFIG_USB_MTU3)		+= mtu3/
 
 obj-$(CONFIG_PCI)		+= host/
 obj-$(CONFIG_USB_EHCI_HCD)	+= host/