manifest.xml: Remove OMX from device manifest am: f02f9af6b0 am: 6b31fd2c53

Original change: https://android-review.googlesource.com/c/device/linaro/dragonboard/+/2973951

Change-Id: Ie17c5a1445df20c07d9003be99e7efd1c5f5fe4a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>