wifi: iwlwifi: mvm: don't drop unencrypted MCAST frames

wifi: iwlwifi: mvm: don't drop unencrypted MCAST frames

MCAST frames are filtered out by the driver if we are not
authorized yet.
Fix it to filter out only protected frames.

Fixes: 147eb05f24e6 ("iwlwifi: mvm: always tell the firmware to accept MCAST frames in BSS")
Signed-off-by: Ayala Beker <ayala.beker@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230413213309.9cedcc27db60.I8fb7057981392660da482dd215e85c15946d3f4b@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>