Input: adp5588-keys - use devm_regulator_get_enable()

Use devm_regulator_get_enable() instead of hand writing it. It saves some
line of code.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Link: https://lore.kernel.org/r/af343b5b0d740cc9f8863264c30e3da4215721d7.1686985911.git.christophe.jaillet@wanadoo.fr


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>