Input: colibri-vf50-ts - don't depend on VF610_ADC

Any IIO ADC can be used with the driver, so do not depend
on VF610_ADC.

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>
Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://lore.kernel.org/r/20220712101619.326120-2-francesco.dolcini@toradex.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>