ASoC: rockchip: add workaround for silence of rk3288 ACODEC

This patch adds reset and precharge in shutdown of PCM device.

ACODEC goes to silence if we change Fs to 44.1kHz from 48kHz. This
workaround seems to work but I don't know this workaround is correct
sequence or not for ACODEC.

Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
Signed-off-by: Mark Brown <broonie@kernel.org>