iwlwifi: mvm: support absolute thresholds in bf configuration

Update iwl_beacon_filter_cmd to support
BEACON_FILTER_CONFIG_API_S_VER_4.

Currently driver configs them to be zero
(i.e. disable them, so no change is applied).

Signed-off-by: Avigail Grinstein <avigail.grinstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>