meta-angstrom: Add LAYERSERIES_COMPAT markup to layer.conf
meta-angstrom: Add LAYERSERIES_COMPAT markup to layer.conf

Signed-off-by: Max Krummenacher <2adf29ceaf73d2cea8fff1ff57e7b25e74cc8f1f@toradex.com>

Angstrom-distribution/meta-angstrom,Angstrom-distribution/meta-angstrom,Angstrom-distribution/meta-angstrom,Angstrom-distribution/meta-angstrom