Merge "Enable serial console on dragonboard devices." am: b539f3164c am: 3cb0e3d5d1

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2103407

Change-Id: I5321dbb06f6941411f34ae6cbc86eb1544e7d0d0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>