Subject: ALSA: seq: Remove autoload locks in driver registration

Since we're calling request_module() asynchronously now, we can get
rid of the autoload lock in snd_seq_device_register_driver(), as well
as in the snd-seq driver registration itself.  This enables the
automatic loading of dependent sequencer modules, such as
snd-seq-virmidi from snd-emu10k1-synth.

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