leds: tlc591xx: Replace of_node_put to __free

leds: tlc591xx: Replace of_node_put to __free

Use __free() for device_node values, and thus drop calls to
of_node_put().

The variable attribute __free() adds a scope based cleanup to
the device node. The goal is to reduce memory management issues
in the kernel code.

The for_each_available_child_of_node() was replaced to the equivalent
for_each_available_child_of_node_scoped() which uses the __free().

Suggested-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Marilene A Garcia <marilene.agarcia@gmail.com>
Link: https://lore.kernel.org/r/20240611001740.10490-1-marilene.agarcia@gmail.com
Signed-off-by: Lee Jones <lee@kernel.org>