ALSA: firewire-lib: pass packet descriptor to data block processing layer

This commit changes signature of callback function to call data block
processing layer with packet descriptor. At present, the layer is called
per packet.

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