ASoC: wm8997: Replace usage deprecated MUX/ENUM macros

SOC_VALUE_ENUM, SND_SOC_DAPM_VALUE_MUX and SOC_DAPM_VALUE_ENUM are deprecated
and merely an alias for SOC_ENUM, SND_SOC_DAPM_MUX and SOC_DAPM_ENUM. Replace
the deprecated macros so we can eventually remove their definition.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@linaro.org>