Remove bm_poseur, unmaintained and obsolete

The bm_poseur git repository link has been broken
for over 11 months. The virtualized/fake baremetal
environment is not working and has not worked in a
long time. Now, on the tail of enabling 'enable -o errexit',
this functionality now has a hard break.

Change-Id: I3cbd8db58c422bc5273d2433278aaa5e449ecfd9
Closes-Bug: 1285954
Merge "Remove bm_poseur, unmaintained and obsolete"