mtd: rawnand: mtk: Use for_each_child_of_node_scoped()

[ Upstream commit 87959526 ]

Avoids the need for manual cleanup of_node_put() in early exits
from the loop.

Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Link: https://lore.kernel.org/linux-mtd/20240826094328.2991664-8-ruanjinjie@huawei.com


Stable-dep-of: 2073ae37 ("mtd: rawnand: mtk: Fix init error path")
Signed-off-by: Sasha Levin <sashal@kernel.org>