ASoC: cs35l56: Set correct upper volume limit

ASoC: cs35l56: Set correct upper volume limit

Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:

These two commits set the upper limit of the Speaker Volume control
to +12dB instead of +100dB.

This should have been a simple 1-line change to the #define in the
header file, but only the HDA cs35l56 driver is using this define.
The ASoC cs35l56 driver was using hardcoded numbers instead of the
header defines.

So the first commit changes the ASoC driver to use the #defined
constants. The second commit corrects the value of the constant.