romulus: drop meta-ibm from build default

Base hardware enablement support for meta-romulus is provided by
meta-romulus and meta-openpower.  meta-ibm adds advanced serviceability
functions for IBM branded products backed by the IBM service structure.

Romulus is a reference platform for ODMs and/or OEMS building POWER9
based systems.  End users cannot purchase support contracts for Romulus
systems.  As such remove meta-ibm from the build configuration in the
spirit of keeping the reference implementation mini and simplified.

At a functional level this removes the ibm-logging application from
images.

Note that meta-ibm can always be re-integrated by simply adding it to
bblayers.conf

Change-Id: If6590d768fcd74dacc65deb400bf83acf1fb033c
1 file changed