iio: adc: ad7380: add missing supplies

vcc and vlogic are required but are not retrieved and enabled in the
probe. Add them.

In order to prepare support for additional parts requiring different
supplies, add vcc and vlogic to the platform specific structures

Reviewed-by: Nuno Sa <nuno.sa@analog.com>
Reviewed-by: David Lechner <dlechner@baylibre.com>
Signed-off-by: Julien Stephan <jstephan@baylibre.com>
Link: https://patch.msgid.link/20241022-ad7380-fix-supplies-v3-3-f0cefe1b7fa6@baylibre.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>