[PATCHv2 3/3] iio: ad5064: Always use external vref if there is no internal vref

If the device does not have an internal reference, there is no other choice but to use the external reference. In that case, it does not make much sense to have to specify it. This patch ensures that the external reference is used if the device does not feature an internal reference.

[PATCHv2 3/3] iio: ad5064: Always use external vref if there is no internal vref

If the device does not have an internal reference, there is no other choice but to use the external reference. In that case, it does not make much sense to have to specify it. This patch ensures that the external reference is used if the device does not feature an internal reference.