ASoC: rt5670: Add JD and push button support

This patch add JD and push button support for rt5670.
rt5670_mic_detect should be called in machine driver to support
this function. A correct value of i2c->irq and rt5670->pdata.jd_mode
are also necessary for it.

Signed-off-by: Bard Liao <bardliao@realtek.com>