i2c: mxs: Remove unneeded platform_device_id

The i2c-mxs driver only runs on DT-platform and there is no
need to use the platform_device_id structure to pass the driver
data.

Get rid of it to make the code simpler.

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>