uwb: depend on EXPERIMENTAL

The UWB stack has some sysfs APIs that will change thus it's best
marked as EXPERIMENTAL until these APIs are finalized.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
diff --git a/drivers/usb/wusbcore/Kconfig b/drivers/usb/wusbcore/Kconfig
index 4ea7669..eb09a0a 100644
--- a/drivers/usb/wusbcore/Kconfig
+++ b/drivers/usb/wusbcore/Kconfig
@@ -2,7 +2,8 @@
 # Wireless USB Core configuration
 #
 config USB_WUSB
-	tristate "Enable Wireless USB extensions"
+	tristate "Enable Wireless USB extensions (EXPERIMENTAL)"
+	depends on EXPERIMENTAL
 	depends on USB
         select UWB
         select CRYPTO