iio: adc: twl4030: Fix ADC[3:6] readings
iio: adc: twl4030: Fix ADC[3:6] readings

MADC[3:6] reads incorrect values without these two following changes:

- enable the 3v1 bias regulator for ADC[3:6]
- configure ADC[3:6] lines as input, not as USB

Signed-off-by: Adam YH Lee <aa28ee08db6737a718bd8454760cefe8d54c851d@gmail.com>
Signed-off-by: Jonathan Cameron <09f65b71b7655725897b2fd41a09a0cefe2e1ace@kernel.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs