Revert "ALSA: ump: Don't enumeration invalid groups for legacy rawmidi"

This reverts commit c2d188e1.

Although it's fine to filter the invalid UMP groups at the first probe
time, this will become a problem when UMP groups are updated and
(re-)activated.  Then there is no way to re-add the substreams
properly for the legacy rawmidi, and the new active groups will be
still invisible.

So let's revert the change.  This will move back to showing the full
16 groups, but it's better than forever lost.

Link: https://patch.msgid.link/20241230114023.3787-1-tiwai@suse.de


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