ALSA: rawmidi: Expose the tied device number in info ioctl

The UMP legacy rawmidi is derived from the UMP rawmidi, but currently
there is no way to know which device is involved in other side.

This patch extends the rawmidi info ioctl to show the tied device
number.  As default it stores -1, indicating that no tied device.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20250110155943.31578-2-tiwai@suse.de