linux-phytec-fsl

iwlwifi: remove support for fw older than -17 and -22

FW versions older than -17 for 3160 and 7260 and older than -22 for
newer NICs are not supported anymore.  Don't load these versions
and remove code that handles them.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>