meta-phosphor: remove custom BBFILE_COLLECTION parsing

Switch from custom BBFILE_COLLECTION parsing to relying on
BBFILES_DYNAMIC for any new layers.  The existing layers (aspeed,
nuvoton) have already been moved to the BBFILES_DYNAMIC mechanism.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ie67b95684349b6419e4608afba660607d0566803
diff --git a/meta-phosphor/conf/layer.conf b/meta-phosphor/conf/layer.conf
index 0041dfc..28d17d5 100644
--- a/meta-phosphor/conf/layer.conf
+++ b/meta-phosphor/conf/layer.conf
@@ -12,14 +12,6 @@
 
 IMAGE_FEATURES[validitems] += "tools-profile"
 
-# Let us add layer-specific bbappends which are only applied when that
-# layer is included in our configuration
-BBFILES += "${@' '.join('${LAYERDIR}/%s/recipes*/*/*.bbappend' % layer \
-               for layer in BBFILE_COLLECTIONS.split())}"
-# Add layer-specific bb files too
-BBFILES += "${@' '.join('${LAYERDIR}/%s/recipes*/*/*.bb' % layer \
-               for layer in BBFILE_COLLECTIONS.split())}"
-
 BBFILES_DYNAMIC += " \
     aspeed-layer:${LAYERDIR}/dynamic-layers/aspeed-layer/recipes-*/*/*.bb \
     aspeed-layer:${LAYERDIR}/dynamic-layers/aspeed-layer/recipes-*/*/*.bbappend \