firmware: cw1200: Add firmware for the ST-E CW1200 WLAN chipset.

This firmware file supports rev 2.2 of the CW1100/CW1200 family.

Signed-off-by: Jean Philippe PERRIN <j.p.perrin@st.com>
Signed-off-by: Solomon Peachy <pizza@shaftnet.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>