platform: arm64: lenovo-yoga-c630: use the auxiliary device creation helper

platform: arm64: lenovo-yoga-c630: use the auxiliary device creation helper

The auxiliary device creation of this driver is simple enough to
use the available auxiliary device creation helper.

Use it and remove some boilerplate code.

Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Link: https://lore.kernel.org/r/20250610-yoga-aux-v1-1-d6115aa1683c@baylibre.com
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>