adc: rockchip-saradc: add support for getting reference voltage value

Mirroring commit 97ab802aa36f ("adc: meson-saradc: add support for
getting reference voltage value") for meson-saradc, this adds support
for getting the "vref-supply" regulator and register it as the ADC's
reference voltage regulator, so clients can translate sampled ADC values
to voltage.

Signed-off-by: Peter Cai <[email protected]>
Reviewed-by: John Keeping <[email protected]>
Tested-by: John Keeping <[email protected]>
Cc: Simon Glass <[email protected]>
Cc: Philipp Tomsich <[email protected]>
Cc: Kever Yang <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Reviewed-by: Kever Yang <[email protected]>

0 files changed, 0 insertions, 0 deletions