ALSA: ControlName.txt: Add 'Analogue' as a prefix for volume controls

Currently 'Playback Volume' is the correct way to express an analogue
volume control. However, this control name has initialisation defaults
applied when using 'alsactl restore' and in some cases this is not
appropriate. An example would be a control that has a selection of
0db and -6dB of gain that is intended to set the fullscale ouput
voltage of a DAC. The TI pcm512x family of DAcs have such a control.
In this case the device/driver reset defaults are preferred.

Signed-off-by: Howard Mitchell <hm@hmbedded.co.uk>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>