firewire-lib/fireworks: Add a quirk for empty packet with TAG0

Fireworks has a quirk to tranmit empty packets with TAG0. This commit
is to avoid side effect for the other devices.
firewire-lib/fireworks: rename a quirk of rx packets for MIDI

Fireworks has a quirk to ignore MIDI messages in data blocks more than 8.
This commit rename an existed flag to keep naming rule.