Merge "dragonboards: Add boot image header v4 support and remove v2" am: 0258a8aa47 am: df69a58b14

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

Change-Id: I375e296af06c5720cfbff93a1586cc86342772b4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>