iwlwifi: mvm: add MVM_FW_BCAST_FILTER_PASS_ALL option

The MVM_FW_BCAST_FILTER_PASS_ALL option defined in iwl-dbg-cfg.ini
configuration file allows to enable/disable FW broadcast filtering.

If MVM_FW_BCAST_FILTER_PASS_ALL is not defined in iwl-dbg-cfg.ini or
its value is 0, the mvm broadcast filtering is enabled.

Setting MVM_FW_BCAST_FILTER_PASS_ALL=1 in iwl-dbg-cfg.ini blocks sending
of BCAST_FILTER_CMD to FW.

Signed-off-by: Max Stepanov <Max.Stepanov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>