ALSA: 6fire: make buffers DMA-able (midi)

commit 4c2aee0032b70083dafebd733ed9c774633b2fa3 upstream.

Patch makes midi output buffer DMA-able by allocating it separately.

Signed-off-by: Torsten Schenk <torsten.schenk@zoho.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>