mmc: tegra: Optimize write_w path for tegra114 and later

Setup a different set of sdhci_ops for tegra114 and later so that
the write_w callback is only used on tegra114. This allows us to
remove the NVQUIRK_SHADOW_XFER_MODE_REG and simply the logic
in tegra_sdhci_writew.

Suggested-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Acked-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>