regulator: scmi: Add missing of_node_get()

In scmi_regulator_probe(), of_find_node_by_name() will decrease
the refcount of its first argument and we need a of_node_get()
to keep reference balance.

Signed-off-by: Liang He <windhl@126.com>
Reviewed-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20220622034816.4094043-1-windhl@126.com


Signed-off-by: Mark Brown <broonie@kernel.org>