commit fdb6eb0a upstream.

When there is prefix specified, currently we will add this prefix in
widget->name, but not in widget->sname.
it causes failure at snd_soc_dapm_link_dai_widgets:

if (!w->sname || !strstr(w->sname, dai_w->name))

because dai_w->name has prefix added, but w->sname does not.
We should also add prefix for stream name
Signed-off-by: Koro Chen <koro.chen@mediatek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
[bwh: Backported to 3.2:
 - Adjust context
 - s/prefix/dapm->codec->name_prefix]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>