dm: test: Add test case for dev_get_dma_ranges()

Introduce some new nodes in sandbox's test device-tree and dm tests in
order to validate dev_get_dma_range().

Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>