i2c: tegra: Remove unnecessary write to INT_STATUS

The write is not necessary and may cause the I2C controller to misbehave.
With this fix, I2C on Tegra30 works (at least, running i2cdump repeatedly
on the WM8903 on Cardhu's I2C5/DVC bus).

Signed-off-by: Alok Chauhan <alokc@nvidia.com>
[swarren: Reworded commit description]
Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>