ASoC: cs35l56: Limit Speaker Volume to +12dB maximum

ASoC: cs35l56: Limit Speaker Volume to +12dB maximum

Change CS35L56_MAIN_RENDER_USER_VOLUME_MAX to 48, to limit the maximum
value of the Speaker Volume control to +12dB. The minimum value is
unchanged so that the default 0dB has the same integer control value.

The original maximum of 400 (+100dB) was the largest value that can be
mathematically handled by the DSP. The actual maximum amplification is
+12dB.

Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Link: https://patch.msgid.link/20240703095517.208077-3-rf@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>