Revert "i2c: tegra: Synchronize DMA before termination"

This reverts commit 8814044f

 because
regressions were showing up.

Suggested-by: Thierry Reding <treding@nvidia.com>
Link: https://lore.kernel.org/dmaengine/20200319201140.17451-1-digetx@gmail.com/
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>