iwlwifi: Fix HT compilation breakage caused by cfg80211 API for channels/bitrates patch

This patch fixes compilation breakage caused by 'cfg80211 API for
channels/bitrates' patch.
however it doesn't fix the driver's functional problems caused by that
patch.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>