ASoC: rt5682: enable fast discharge for headset unplugging

To avoid the pop noise, this patch enables the feature of fast discharge.

Signed-off-by: Shuming Fan <shumingf@realtek.com>
Link: https://lore.kernel.org/r/20210111092544.9064-1-shumingf@realtek.com
Signed-off-by: Mark Brown <broonie@kernel.org>