regulator: tps62360: dt: initialize of_node param for regulator register.

Initialize config.of_node for regulator before registering.
This is needed for DT based regulator support.
Regulator stores this of_node value in rdev->dev.of_node
and used for lookup when client ask for regulator_get().

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>