i2c: tegra: Always terminate DMA transfer

It is possible that I2C could error out in the middle of DMA transfer and
in this case DMA channel needs to be reset, otherwise a follow up transfer
will fail because DMA channel stays blocked.

Tested-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>