ASoC: arizona: Add utility function to check if an input is analog

We will occasionally require to take different action based on if an
input is analog or digital so add a helper function to return if an
input is analog.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
2 files changed