Add Portwell Neptune machine

Initial introduction of Portwell Neptune family equipped with
Aspeed 2500 BMC SoC.

Tested: Build portwell neptune board and load on the target hardware.
Ensure that BMC boots to console.

Change-Id: I7a97162dfe3031904e27f2de2691e693079c9216
Signed-off-by: Amithash Prasad <amithash@fb.com>
diff --git a/meta-neptune/conf/layer.conf b/meta-neptune/conf/layer.conf
new file mode 100644
index 0000000..5e44606
--- /dev/null
+++ b/meta-neptune/conf/layer.conf
@@ -0,0 +1,9 @@
+# We have a conf and classes directory, add to BBPATH
+BBPATH .= ":${LAYERDIR}"
+
+# We have recipes-* directories, add to BBFILES
+BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
+            ${LAYERDIR}/recipes-*/*/*.bbappend"
+
+BBFILE_COLLECTIONS += "neptune"
+BBFILE_PATTERN_neptune = ""