usb: gadget: don't couple configfs to legacy gadgets

It's perfectly fine to have all configfs functions
built-in while having modular legacy gadgets. Let's
allow for that.
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/Kconfig

@@ -209,25 +209,6 @@ config USB_F_PRINTER
 config USB_F_TCM
 	tristate
 
-choice
-	tristate "USB Gadget Drivers"
-	default USB_ETH
-	help
-	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
-	  driver through the abstract "gadget" API.  Some other operating
-	  systems call these "client" drivers, of which "class drivers"
-	  are a subset (implementing a USB device class specification).
-	  A gadget driver implements one or more USB functions using
-	  the peripheral hardware.
-
-	  Gadget drivers are hardware-neutral, or "platform independent",
-	  except that they sometimes must understand quirks or limitations
-	  of the particular controllers they work with.  For example, when
-	  a controller doesn't support alternate configurations or provide
-	  enough of the right types of endpoints, the gadget driver might
-	  not be able work with that controller, or might need to implement
-	  a less common variant of a device class protocol.
-
 # this first set of drivers all depend on bulk-capable hardware.
 
 config USB_CONFIGFS
@@ -475,6 +456,25 @@ config USB_CONFIGFS_F_TCM
 	  Both protocols can work on USB2.0 and USB3.0.
 	  UAS utilizes the USB 3.0 feature called streams support.
 
+choice
+	tristate "USB Gadget Drivers"
+	default USB_ETH
+	help
+	  A Linux "Gadget Driver" talks to the USB Peripheral Controller
+	  driver through the abstract "gadget" API.  Some other operating
+	  systems call these "client" drivers, of which "class drivers"
+	  are a subset (implementing a USB device class specification).
+	  A gadget driver implements one or more USB functions using
+	  the peripheral hardware.
+
+	  Gadget drivers are hardware-neutral, or "platform independent",
+	  except that they sometimes must understand quirks or limitations
+	  of the particular controllers they work with.  For example, when
+	  a controller doesn't support alternate configurations or provide
+	  enough of the right types of endpoints, the gadget driver might
+	  not be able work with that controller, or might need to implement
+	  a less common variant of a device class protocol.
+
 source "drivers/usb/gadget/legacy/Kconfig"
 
 endchoice