iwlwifi: allow combining different phy images with mac images

Currently there is one to one function between device id to it's ucode.
The new generation devices allows to combine different phy and mac images.
Now we have two different ucode images with the same device id.
Read RF ID to identify phy image and overwrite it if needed.

Signed-off-by: Haim Dreyfuss <haim.dreyfuss@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>