i2c: rk3x: add NULL entry to the end of_device_id array

drivers/i2c/busses/i2c-rk3x.c:610:69-70: rk3x_i2c_match is not NULL terminated at line 610

Make sure of_device_id tables are NULL terminated
Generated by: /kbuild/src/linux/scripts/coccinelle/misc/of_table.cocci

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>