As snd_soc_jack_report() can sleep, move handling of mbhc events to a
thread context rather than in interrupt context.

Fixes: de66b345 ('ASoC: codecs: msm8916-wcd-analog: add MBHC support')
Reported-by: NBjorn Andersson <bjorn.andersson@linaro.org>
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>