west/sign: Move from using partition label property

        flash = edt.chosen_node('zephyr,flash')

        if not flash:

            log.die('devicetree has no chosen zephyr,flash node;',

                    "can't infer flash write block or image-0 slot sizes")

                    "can't infer flash write block or slot0_partition slot sizes")

        return flash

    @staticmethod

    def edt_flash_params(flash):

        # Get the flash device's write alignment and offset from the

        # image-0 partition and the size from image-1 partition, out of the

        # build directory's devicetree. image-1 partition size is used,

        # slot0_partition and the size from slot1_partition , out of the

        # build directory's devicetree. slot1_partition size is used,

        # when available, because in swap-move mode it can be one sector

        # smaller. When not available, fallback to image-0 (single image dfu).

        # smaller. When not available, fallback to slot0_partition (single slot dfu).

        # The node must have a "partitions" child node, which in turn

        # must have child node labeled "image-0" and may have a child node

        # named "image-1". By convention, the slots for consumption by

        # must have child nodes with label slot0_partition and may have a child node

        # with label slot1_partition. By convention, the slots for consumption by

        # imgtool are linked into these partitions.

        if 'partitions' not in flash.children:

            log.die("DT zephyr,flash chosen node has no partitions,",

                    "can't find partitions for MCUboot slots")

        partitions = flash.children['partitions']

        images = {

            node.label: node for node in partitions.children.values()

            if node.label in set(['image-0', 'image-1'])

        slots = {

            label: node for node in partitions.children.values()

                        for label in node.labels

                        if label in set(['slot0_partition', 'slot1_partition'])

        }

        if 'image-0' not in images:

            log.die("DT zephyr,flash chosen node has no image-0 partition,",

        if 'slot0_partition' not in slots:

            log.die("DT zephyr,flash chosen node has no slot0_partition partition,",

                    "can't determine its address")

        # Die on missing or zero alignment or slot_size.

                    'DT flash device write-block-size {}'.format(align))

        # The partitions node, and its subnode, must provide

        # the size of image-1 or image-0 partition via the regs property.

        image_key = 'image-1' if 'image-1' in images else 'image-0'

        if not images[image_key].regs:

            log.die(f'{image_key} flash partition has no regs property;',

                    "can't determine size of image")

        # the size of slot1_partition or slot0_partition partition via the regs property.

        slot_key = 'slot0_partition' if 'slot1_partition' in slots else 'slot0_partition'

        if not slots[slot_key].regs:

            log.die(f'{slot_key} flash partition has no regs property;',

                    "can't determine size of slot")

        # always use addr of image-0, which is where images are run

        addr = images['image-0'].regs[0].addr

        # always use addr of slot0_partition, which is where slots are run

        addr = slots['slot0_partition'].regs[0].addr

        size = images[image_key].regs[0].size

        size = slots[slot_key].regs[0].size

        if size == 0:

            log.die('expected nonzero slot size for {}'.format(image_key))

            log.die('expected nonzero slot size for {}'.format(slot_key))

        return (align, addr, size)