ASoC: rt5659: Separate adc 1/2 clock control

The control bits of ADC 1 and 2 clock are different. We have to
separate it.

Signed-off-by: Zhong An <zhongan@pinecone.net>
Signed-off-by: Bard Liao <bardliao@realtek.com>
Signed-off-by: Mark Brown <broonie@kernel.org>