ARM: tegra: fix Jetson TK1 SD card supply

Regulator vddio_sdmmc3 provides the Tegra<->SD IO voltage, not the card
core supply voltage. That is, it provides vqmmc, not vmmc. Fix the DT to
correctly reflect this.

Reported-by: Andrew Bresticker <abrestic@chromium.org>
Signed-off-by: Stephen Warren <swarren@nvidia.com>