mmc: tegra: fix SDR50 tuning override

mmc: tegra: fix SDR50 tuning override

Commit 8d43f771cc05 inadvertently mixed up a quirk flag's name and
broke SDR50 tuning override. Use correct NVQUIRK_ name.

Fixes: 8d43f771cc05 ("mmc: tegra: enable UHS-I modes")
Cc: <stable@vger.kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: Thierry Reding <treding@nvidia.com>
Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Link: https://lore.kernel.org/r/9aff1d859935e59edd81e4939e40d6c55e0b55f6.1578390388.git.mirq-linux@rere.qmqm.pl
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>