ASoC: codecs: jz4725b: use right control for Master Playback

ASoC: codecs: jz4725b: use right control for Master Playback

At the moment DAC control is used as Master Playback control, this is
incorrect as DAC's output goes to a Mixer.

The Mixer couples analog input from 4 sources (DAC, Line In, Mic 1,
 Mic 2) each input has its own gain & mute controls.

Output of the Mixer goes to Output Stage control which is the best suite
for the new Playback Master. However, it doesn't have mute capability.

The patch implements Output Stage control as a new master and renames
old Master to DAC. Rest of mixer inputs will be implemented in the next
patch in the series.

Manual states that Output stage control (16.6.3.5 Programmable output
amplifier: PGAT) gain varies from -33.5dB to +4.5dB, gain step isn't
fixed and has 3 opts.

Signed-off-by: Siarhei Volkau <lis8215@gmail.com>
Link: https://lore.kernel.org/r/20221016132648.3011729-6-lis8215@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>