ASoC: qcom: apq8016-sbc: add mic support

This patch add mic support on apq8016-sbc board aka db410c. Tested it
with headset mic.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Acked-by: Kenneth Westfield <kwestfie@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>