ALSA: firewire-motu: cancel chunk alignment for protocol version 2

For MOTU protocol version 2, this driver arranges the number of data
chunks to align chunks to quadlet data channel. However, MOTU Traveler
has padding bytes in the end of data block at high clock mode.

This commit removes the arrangement. Fortunately, at low and middle clock
mode, supported model for v2 protocol (828mkII) gets no influence from this
change because all of combination for data chunks are just aligned to
quadlet data channel.

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