iwlwifi: support two phys for a000 devices

Support differentiating between two phys for a000 devices
in order to load the correct firmware.
Eventually when moving completely to the new phy we will be
able to remove this.

Signed-off-by: Sara Sharon <sara.sharon@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>