dm: Introduce xxx_get_dma_range()

Add the following functions to get a specific device's DMA ranges:
 - dev_get_dma_range()
 - ofnode_get_dma_range()
 - of_get_dma_range()
 - fdt_get_dma_range()
They are specially useful in oder to be able validate a physical address
space range into a bus's and to convert addresses from and to address
spaces.

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>