of: dynamic: Add interfaces for creating device node dynamically

of_changeset_create_node() creates device node dynamically and attaches
the newly created node to a changeset.

Expand of_changeset APIs to handle specific types of properties.
    of_changeset_add_prop_string()
    of_changeset_add_prop_string_array()
    of_changeset_add_prop_u32_array()

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Lizhi Hou <lizhi.hou@amd.com>
Link: https://lore.kernel.org/r/1692120000-46900-2-git-send-email-lizhi.hou@amd.com
Signed-off-by: Rob Herring <robh@kernel.org>