ALSA: sb_mixer: convert pointer tables to mixer control tables

Convert table of pointers to mixer controls into tables
of the mixer controls. It saves about 20% of the snd-sb-common
module size reported by lsmod.

The als4000 uses part of sb16's control table.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Takashi Iwai <tiwai@suse.de>