usb: add support for generic EHCI devices

This driver is meant to be used with any EHCI-compatible host
controller in case if there's no need for platform-specific
glue such as setup of controller or PHY's power mode via
GPIOs etc.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Stephen Warren <swarren@nvidia.com>
Cc: Simon Glass <sjg@chromium.org>
Cc: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/host/Kconfig b/drivers/usb/host/Kconfig
index 2a2bffe..0096a2f 100644
--- a/drivers/usb/host/Kconfig
+++ b/drivers/usb/host/Kconfig
@@ -73,4 +73,12 @@
 	---help---
 	  Enables support for the on-chip EHCI controller on UniPhier SoCs.
 
+config USB_EHCI_GENERIC
+	bool "Support for generic EHCI USB controller"
+	depends on OF_CONTROL
+	depends on DM_USB
+	default n
+	---help---
+	  Enables support for generic EHCI controller.
+
 endif