ASoC: codecs: wcd938x: Unify define used for MIC2 bias register

ASoC: codecs: wcd938x: Unify define used for MIC2 bias register

There is a define for MIC bias registers enable mask called
WCD938X_MICB_EN_MASK, which is already used to handle all four MIC1-4
biases in wcd938x_mbhc_micb_adjust_voltage().

Use the same define also in wcd938x_mbhc_micb_en_status() for MIC2 to
have unified, simpler approach.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://msgid.link/r/20240523104228.36263-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>