USB: fix the USB_GADGET_DUMMY_HCD dependencies

If USB=m, USB_GADGET=y, the option USB_GADGET_DUMMY_HCD mustn't be 
offered since selecting it results in a compile error.

This patch fixes kernel Bugzilla #6534 reported by Toralf Förster.

Signed-off-by: Adrian Bunk <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: AdrianBunk

drivers/usb/gadget/Kconfig

@@ -207,7 +207,7 @@ config USB_AT91
 
 config USB_GADGET_DUMMY_HCD
 	boolean "Dummy HCD (DEVELOPMENT)"
-	depends on USB && EXPERIMENTAL
+	depends on (USB=y || (USB=m && USB_GADGET=m)) && EXPERIMENTAL
 	select USB_GADGET_DUALSPEED
 	help
 	  This host controller driver emulates USB, looping all data transfer