mmc: tegra: disable UHS modes

Program TEGRA_SDHCI_VENDOR_MISC_CTRL so that UHS modes aren't advertised
in SDHCI_CAPABILITIES_1.  While the Tegra SDHCI controller does support
these modes, they require Tegra-specific tuning and calibration routines
which the driver does not support yet.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Tested-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Chris Ball <chris@printf.net>