iwlwifi: removing IWL4965_HT config

This patch removes CONFIG_IWL4965_HT #ifdefs for iwl 4965 and 5000. 11n
feature is stable in those drivers and its mode of operation is determined
in mac80211, so this dependency is not needed any more.

Signed-off-by: Ron Rindjunsky <ron.rindjunsky@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>