ALSA: seq: ump: Handle FB info update

This patch implements the handling of the dynamic update of FB info.

When the FB info update is received after the initial parsing, it
means the dynamic FB info update.  We compare the result, and if the
actual update is detected, it's notified via a new ops,
notify_fb_change, to the sequencer client, and the corresponding
sequencer ports are updated accordingly.

Link: https://lore.kernel.org/r/20230612081054.17200-7-tiwai@suse.de


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