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-portwell/meta-neptune/conf/bblayers.conf.sample b/meta-portwell/meta-neptune/conf/bblayers.conf.sample
new file mode 100644
index 0000000..3f62504
--- /dev/null
+++ b/meta-portwell/meta-neptune/conf/bblayers.conf.sample
@@ -0,0 +1,20 @@
+# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
+# changes incompatibly
+LCONF_VERSION = "7"
+
+BBPATH = "${TOPDIR}"
+BBFILES ?= ""
+
+BBLAYERS ?= " \
+  ##OEROOT##/meta \
+  ##OEROOT##/meta-poky \
+  ##OEROOT##/import-layers/meta-openembedded/meta-oe \
+  ##OEROOT##/import-layers/meta-openembedded/meta-networking \
+  ##OEROOT##/import-layers/meta-openembedded/meta-perl \
+  ##OEROOT##/import-layers/meta-openembedded/meta-python \
+  ##OEROOT##/import-layers/meta-virtualization \
+  ##OEROOT##/meta-phosphor \
+  ##OEROOT##/meta-openbmc-bsp/meta-aspeed \
+  ##OEROOT##/meta-openbmc-bsp/meta-aspeed/meta-ast2500 \
+  ##OEROOT##/meta-openbmc-machines/meta-x86/meta-portwell/meta-neptune \
+  "