ALSA: remove CONFIG_KMOD from sound

A bunch of things in alsa depend on CONFIG_KMOD,
use CONFIG_MODULES instead where the dependency
is needed at all.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Jaroslav Kysela <perex@perex.cz>