Add missing USRobotics Wireless Adapter (Model 5423) id into zd1211rw

USRobotics Wireless Adapter (Model 5423) works well with current
zd1211rw driver also (i have tested 2.6.18, 2.6.20 and 2.6.21-rc7).

It just needs its ID added to the list of devices.

Signed-off-by: S.Çağlar Onur <caglar@pardus.org.tr>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>