regulator: rc5t583: Get rid of struct rc5t583_regulator

The struct rc5t583_regulator only has 2 members, the *rdev is no longer
used because this driver is using devm_regulator_register now. After remove
*rdev, only *reg_info left. We can use struct rc5t583_regulator_info
directly, so remove struct rc5t583_regulator.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@kernel.org>