ASoC: tlv320aic3x: add input clock selection

This patch adds input selection of main codec clock - from what pin.
Both registers set same value since codec uses clock divider or pll at one time.

Signed-off-by: Jiri Prchal <jiri.prchal@aksignal.cz>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>