ASoC: tlv320adcx140: Add controls for PDM clk

Add ALSA controls to configure the PDM clocks.
The clocks need to be configurable to accommodate various microphones
that use clocks for low power/low resolution modes to high power/high
resolution modes.

Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200514123338.20392-1-dmurphy@ti.com


Signed-off-by: Mark Brown <broonie@kernel.org>