Merge "dragonboards: Add boot image header v4 support and remove v2" am: 0258a8aa47

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2103029

Change-Id: I1f701679c8a34ae81d764ac08595bb9cb1856af3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>