i2c: davinci: Use platform table macro over module_alias

Generates the same platform module alias. More standard usage.

Signed-off-by: Andrew Davis <afd@ti.com>
Reviewed-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
[wsa: rebased to i2c/for-mergewindow]
Signed-off-by: Wolfram Sang <wsa@kernel.org>