mac80211/rt2x00: sync Rt3352 support

The original patch was accepted into linux-next in a slightly modified form.
In order to provide integrity to follow-up patches, replace the patch in OpenWrt
with the (semantically identical) now upstream patch.
(commit 03839951515b0ea2b21d649b1fe7b63f9817d0c8 in wireless-testing)

Signed-off-by: Daniel Golle <dgolle@allnet.de>

SVN-Revision: 33615