of: dynamic: Add interfaces for creating device node dynamically

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 <[email protected]>
Signed-off-by: Lizhi Hou <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Rob Herring <[email protected]>