ASoC: tlv320adcx140: Fix bias config values

The device tree binding declares the ti,mic-bias-source and the
ti,vref-source properties as u32.  The code reads them as u8 which is
incorrect.  Since the device tree binding indicates them as u32 the
conde needs to be updated to read u32.

In addition the bias source needs to be shifted 4 bits to
correctly write the register.

driver family")

Fixes: 37bde5acf040 ("ASoC: tlv320adcx140: Add the tlv320adcx140 codec
Signed-off-by: Dan Murphy <dmurphy@ti.com>
Link: https://lore.kernel.org/r/20200513142807.11802-1-dmurphy@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>