driver: i2c: Disable dma in I2C-VI by default

driver: i2c: Disable dma in I2C-VI by default

Sets Dma in I2C-VI driver to disabled by default. Removes double
negative by changing var name.

Bug 200302441

Change-Id: Ic56b760f22bc97c90d3fc1cb7a36f7cf217f5640
Reviewed-on: http://git-master/r/1479306
Tested-by: Jacob Rampertab <jrampertab@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: David Wang (SW-TEGRA) <davidw@nvidia.com>
Reviewed-by: Bhanu Murthy V <bmurthyv@nvidia.com>
GVS: Gerrit_Virtual_Submit
Reviewed-by: Shardar Mohammed <smohammed@nvidia.com>
Reviewed-by: Frank Chen <frankc@nvidia.com>
Reviewed-by: Jihoon Bang <jbang@nvidia.com>