ALSA: firewire-motu: parse messages for input parameters in register DSP model

This commit parses message and cache current parameters of input function,
available for MOTU Ultralite, 4 pre, and Audio Express.

Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Link: https://lore.kernel.org/r/20211015080826.34847-9-o-takashi@sakamocchi.jp


Signed-off-by: Takashi Iwai <tiwai@suse.de>