of/platform: Simplify with scoped for each OF child

Use scoped for_each_child_of_node_scoped() when iterating over device
nodes to make code a bit simpler.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://lore.kernel.org/r/20240826062408.2406734-3-ruanjinjie@huawei.com


Signed-off-by: Rob Herring (Arm) <robh@kernel.org>