ASoC: rt5645: remove unused field in pdata

We can know if dmic is used by reading the value of dmic1_data_pin
and dmic2_data_pin. Also IRQ must be used if codec JD or button
detection function is used. So, dmic_en and en_jd_func can be remove
from platform data.

Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>