usb: gadget: allow to enable legacy drivers without USB_ETH

Considerable time ago the legacy gadget menu was added inside the
USB_ETH choice. I think this was a mistake and that the legacy
gadget menu should have been added after "endchoice" instead of
before. Hence this patch.

Fixes: commit 8443f2d2b778 ("usb: gadget: Gadget directory cleanup - group legacy gadgets")
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Nicholas Bellinger <nab@linux-iscsi.org>
Cc: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

drivers/usb/gadget/Kconfig

@@ -508,8 +508,8 @@ choice
 	  controller, and the relevant drivers for each function declared
 	  by the device.
 
-source "drivers/usb/gadget/legacy/Kconfig"
-
 endchoice
 
+source "drivers/usb/gadget/legacy/Kconfig"
+
 endif # USB_GADGET

drivers/usb/gadget/legacy/Kconfig

@@ -13,6 +13,14 @@
 # both kinds of controller can also support "USB On-the-Go" (CONFIG_USB_OTG).
 #
 
+menuconfig USB_GADGET_LEGACY
+	bool "Legacy USB Gadget Support"
+	help
+	   Legacy USB gadgets are USB gadgets that do not use the USB gadget
+	   configfs interface.
+
+if USB_GADGET_LEGACY
+
 config USB_ZERO
 	tristate "Gadget Zero (DEVELOPMENT)"
 	select USB_LIBCOMPOSITE
@@ -490,3 +498,5 @@ config USB_G_WEBCAM
 
 	  Say "y" to link the driver statically, or "m" to build a
 	  dynamically linked module called "g_webcam".
+
+endif