They just called audio_pcm_sw_read/write anyway, so it makes no sense
to have them too.  (The noaudio's read is the only exception, but it
should work with the generic code too.)

Signed-off-by: Kővágó, Zoltán <DirtY.iCE.hu@gmail.com>
Message-id: 92ddc98133bc4b687c6e4608b9321e7b64c0e496.1566168923.git.DirtY.iCE.hu@gmail.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>