Basic support for Firestone and Garrison systems

Firestone and Garrison are IBM branded OpenPOWER systems.
diff --git a/meta-openbmc-machines/meta-openpower/meta-ibm/meta-firestone/conf/bblayers.conf.sample b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-firestone/conf/bblayers.conf.sample
new file mode 100644
index 0000000..c675a18
--- /dev/null
+++ b/meta-openbmc-machines/meta-openpower/meta-ibm/meta-firestone/conf/bblayers.conf.sample
@@ -0,0 +1,27 @@
+# LAYER_CONF_VERSION is increased each time build/conf/bblayers.conf
+# changes incompatibly
+LCONF_VERSION = "6"
+
+BBPATH = "${TOPDIR}"
+BBFILES ?= ""
+
+BBLAYERS ?= " \
+  ##OEROOT##/meta \
+  ##OEROOT##/meta-yocto \
+  ##OEROOT##/meta-phosphor \
+  ##OEROOT##/meta-openbmc-bsp/meta-aspeed \
+  ##OEROOT##/meta-openbmc-bsp/meta-aspeed/meta-ast2400 \
+  ##OEROOT##/meta-openbmc-machines/meta-openpower \
+  ##OEROOT##/meta-openbmc-machines/meta-openpower/meta-ibm \
+  ##OEROOT##/meta-openbmc-machines/meta-openpower/meta-ibm/meta-firestone \
+  "
+BBLAYERS_NON_REMOVABLE ?= " \
+  ##OEROOT##/meta \
+  ##OEROOT##/meta-yocto \
+  ##OEROOT##/meta-phosphor \
+  ##OEROOT##/meta-aspeed \
+  ##OEROOT##/meta-aspeed/meta-ast2400 \
+  ##OEROOT##/meta-openpower \
+  ##OEROOT##/meta-openpower/meta-ibm \
+  ##OEROOT##/meta-openpower/meta-ibm/meta-firestone \
+  "