usb: dwc3: Add Meson G12A USB Glue

Adds support for Amlogic G12A USB Control Glue HW.

The Amlogic G12A SoC Family embeds 2 USB Controllers :
- a DWC3 IP configured as Host for USB2 and USB3
- a DWC2 IP configured as Peripheral USB2 Only

A glue connects these both controllers to 2 USB2 PHYs, and optionnally
to an USB3+PCIE Combo PHY shared with the PCIE controller.

The Glue configures the UTMI 8bit interfaces for the USB2 PHYs, including
routing of the OTG PHY between the DWC3 and DWC2 controllers, and
setups the on-chip OTG mode selection for this PHY.

This driver sets the OTG capable port as Host mode by default,
the switch to Device mode is to be done in a separate patch.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index bbd8105..25e1a38 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -44,6 +44,14 @@
 	  Select this for Xilinx ZynqMP and similar Platforms.
 	  This wrapper supports Host and Peripheral operation modes.
 
+config USB_DWC3_MESON_G12A
+	bool "Amlogic Meson G12A USB wrapper"
+	depends on DM_USB && USB_DWC3 && ARCH_MESON
+	imply PHY
+	help
+	  Select this for Amlogic Meson G12A Platforms.
+	  This wrapper supports Host and Peripheral operation modes.
+
 config USB_DWC3_UNIPHIER
 	bool "DesignWare USB3 Host Support on UniPhier Platforms"
 	depends on ARCH_UNIPHIER && USB_XHCI_DWC3