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

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

Change-Id: I4edfce4ec6b60850243ac3d9edf771716cbadf0e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>