dm: core: convert of_machine_is_compatible to livetree

Replace in the function of_machine_is_compatible(), the used API
fdt_node_check_compatible() by ofnode_device_is_compatible()
to support a live tree.

Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>