iwlwifi: scan: support FW APIs with variable number of profiles

The FW changed the maximum number of scan offload profiles to 8 in new
APIs.  Support it by changing the scan_offload_profile_cfg struct to be
more dynamic, so we can reuse most of the code and only change size of
the profiles array.

Change-Id: I65210cf541af46e2675a8c764d5871f7f5b070d6
Signed-off-by: Tova Mussai <tova.mussai@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>