[PATCH] ieee80211: export list of bit rates with standard WEXT procddures

The patch replace the way to export the list of bit rates in scan results
from IWEVCUSTOM to SIOCGIWRATE. It also removes the max_rate item exported
with SIOCGIWRATE since this should be done by userspace.

Signed-off-by: Jean Tourrilhes <jt@hpl.hp.com>
Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>