Document the pinctrl bindings used by the SDHCI driver to reconfigure
pad voltages on controllers supporting multiple voltage levels.
Signed-off-by: Aapo Vienamo <avienamo@nvidia.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>