layer.conf: do not force early expansion of BBFILES
layer.conf: do not force early expansion of BBFILES

The BBFILES expression is forcing an early expansion which
results in the BBFILE_COLLECTIONS references in BBFILES being
expanded before all the layers were added to it.

Signed-off-by: Chris Larson <1cd63fa3425fea922ed0faa867d1d1b46e7b9b20@mentor.com>
Tested-by: Cedric Hombourger <46c467793201f254bc47b68e65d834257e59e247@mentor.com>
Signed-off-by: Noor Ahsan <d8217232bc1a4f7ec0617804dec3d117857568ff@mentor.com>

sbabic/meta-swupdate,sbabic/meta-swupdate