usb: dwc3: Add dwc3 glue driver support for STi

This patch adds the ST glue logic to manage the DWC3 HC
on STiH407 SoC family. It configures the internal glue
logic and syscfg registers.

Part of this code been extracted from kernel.org driver
(drivers/usb/dwc3/dwc3-st.c)

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index eb035a4..f797a25 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -47,6 +47,15 @@
 	help
 	  Enables support for the on-chip xHCI controller on Rockchip SoCs.
 
+config USB_XHCI_STI
+	bool "Support for STMicroelectronics STiH407 family on-chip xHCI USB controller"
+	depends on ARCH_STI
+	default y
+	help
+	  Enables support for the on-chip xHCI controller on STMicroelectronics
+	  STiH407 family SoCs. This is a driver for the dwc3 to provide the glue logic
+	  to configure the controller.
+
 config USB_XHCI_ZYNQMP
 	bool "Support for Xilinx ZynqMP on-chip xHCI USB controller"
 	depends on ARCH_ZYNQMP