auxdisplay: lcd2s: Switch to i2c ->probe_new()

The deprecated i2c ->probe() functionality doesn't work with
OF compatible strings, as it only checks for the i2c device id.
While it's not a problem right now, it would still bring a
better code. Switch to the new way of probing.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>