Add HARDWARE section of urnis(4) driver to try to gain more visibility.

MFC after:	3 days

share/man/man4/urndis.4

@@ -29,7 +29,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd September 25, 2014
+.Dd October 2, 2014
 .Dt URNDIS 4
 .Os
 .Sh NAME
@@ -68,6 +68,12 @@ such as those commonly found on Android devices.
 It does not support different media types or options.
 For more information on configuring this device, see
 .Xr ifconfig 8 .
+.Sh HARDWARE
+The
+.Nm
+driver supports the
+.Qq tethering
+functionality of many Android devices.
 .Sh SEE ALSO
 .Xr arp 4 ,
 .Xr cdce 4 ,