regulator: scmi: Fix refcount leak in scmi_regulator_probe

of_find_node_by_name() returns a node pointer with refcount
incremented, we should use of_node_put() on it when done.
Add missing of_node_put() to avoid refcount leak.

Fixes: 0fbeae70

 ("regulator: add SCMI driver")
Signed-off-by: Miaoqian Lin <linmq006@gmail.com>
Link: https://lore.kernel.org/r/20220516074433.32433-1-linmq006@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>