rb5: Set Ethernet MAC address on boot am: a961f043ae am: 9fd963eefd am: 8eac097255

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2737313

Change-Id: I2ffe32cc8a7be043d9046728bd6ac4d015a5f3e0
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>