ALSA: firewire-lib: unify tracing events to 'amdtp_packet' event

Now four events of this module have the same arguments and probe timing.
This commit adds a new event, 'amdtp_packet', and replace them. Filtering
functionality of tracing framework is available to pick up events for
inbound/outbound isochronous packets.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Signed-off-by: Takashi Iwai <tiwai@suse.de>