uwb: create a uwb bus type and add in-range peer devices to it

Documentation/usb/WUSB-Design-overview.txt states that UWB devices seen
by a UWB radio controller are added to /sys/bus/uwb/devices, but this
was not actually being done.  This functionality is needed in order for
UWB peer devices to be enumerated by user mode tools.  This patch
creates a uwb bus type and adds UWB peer devices to it as they are
discovered by the radio controller.

Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/uwb/uwb-internal.h b/drivers/uwb/uwb-internal.h
index 6d1bed1..353c055 100644
--- a/drivers/uwb/uwb-internal.h
+++ b/drivers/uwb/uwb-internal.h
@@ -314,6 +314,7 @@
 
 /* -- UWB Sysfs representation */
 extern struct class uwb_rc_class;
+extern struct bus_type uwb_bus_type;
 extern struct device_attribute dev_attr_mac_address;
 extern struct device_attribute dev_attr_beacon;
 extern struct device_attribute dev_attr_scan;