meta-phosphor: migrate nuvoton-layer to dynamic-layers

The proper way to add extensions to another layer is with
BBFILES_DYNAMIC rather than adding to BBFILES based on
BBFILE_COLLECTIONS.  Move nuvoton-layer to a dynamic-layers subdirectory
and hook into layer.conf using BBFILES_DYNAMIC.

Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
Change-Id: Ic1b1f0ce837a899c5060531735c75c73cf51f1f5
diff --git a/meta-phosphor/conf/layer.conf b/meta-phosphor/conf/layer.conf
index 787b36d..0041dfc 100644
--- a/meta-phosphor/conf/layer.conf
+++ b/meta-phosphor/conf/layer.conf
@@ -23,4 +23,6 @@
 BBFILES_DYNAMIC += " \
     aspeed-layer:${LAYERDIR}/dynamic-layers/aspeed-layer/recipes-*/*/*.bb \
     aspeed-layer:${LAYERDIR}/dynamic-layers/aspeed-layer/recipes-*/*/*.bbappend \
+    nuvoton-layer:${LAYERDIR}/dynamic-layers/nuvoton-layer/recipes-*/*/*.bb \
+    nuvoton-layer:${LAYERDIR}/dynamic-layers/nuvoton-layer/recipes-*/*/*.bbappend \
 "