deploy-images: fix name extraction pattern
deploy-images: fix name extraction pattern

With 4.1 images contain the root device in image name to avoid conflicts
between images for internal storage and several external boot devices.
The affected pattern received appropriate upgrade.

Signed-off-by: Jens Rehsack <69d49c504a9219a55b8be0f905e8fe3c32ffb57f@netbsd.org>

tobw/meta-jens,rdm-dev/meta-jens,tobw/meta-jens,rdm-dev/meta-jens,rdm-dev/meta-jens,tobw/meta-jens,rdm-dev/meta-jens,tobw/meta-jens