mmc: sdhci: at91: Use sdhci_set_power_and_voltage()

The sdhci core provides a helper function with the same functionality as
this controller's set_power() callback. Use it instead.

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20200306174413.20634-5-nsaenzjulienne@suse.de


Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>