Latest NVIDIA GPU card has USB Type-C interface. There is a
Type-C controller which can be accessed over I2C.

This driver adds I2C bus driver to communicate with Type-C controller.
I2C client driver will be part of USB Type-C UCSI driver.
Signed-off-by: NAjay Gupta <ajayg@nvidia.com>
Reviewed-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
[wsa: kept Makefile sorting]
Signed-off-by: NWolfram Sang <wsa@the-dreams.de>