regulator: ltc3589: Remove unnecessary MODULE_ALIAS()

The driver has a I2C device id table that is used to create the modaliases
and already contains a "ltc3589" device id. So the modalias is unnecessary.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>