[ALSA] opl3 - Use hwdep for patch loading

Use the hwdep device for loading OPL2/3 patch data instead of the
messy sequencer instrument layer.
Due to this change, the sbiload program should be updated, too.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>