BugLink: http://bugs.launchpad.net/bugs/697240

If the "Volume" suffix is not given, alsa-lib gets confused and
loses the dB information at the simple element level.

Boosts generally affects both playback and capture, as they are
applied early in the chain. Hence no "Playback" or "Capture" in
the suffix.
Signed-off-by: David Henningsson <david.henningsson@canonical.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>