iwlwifi: unify 4965 and 5000 scanning code

This patch unifies 4965 and 5000 scanning code.

We increases the version number to 1.3.27. Since new uCode
iwlwifi-4965-2.ucode is required for 4965 cards.

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