media: nxp: Use devm_kmemdup to replace devm_kmalloc + memcpy

Use the helper function devm_kmemdup() rather than duplicating its
implementation, which helps to enhance code readability.

Signed-off-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>