Add two bindings
test-bindings/multidir.yaml
test-bindings-2/multidir.yaml
and a new test-multidir.dts with two nodes that use them.
Verify that the two bindings were found by checking the
Device.binding_path attribute for the two device nodes.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>