Move palmetto configuration to openpower layer

Added openpower.inc for any openpower system.
Added ibm.cin for IBM openpower systems.
diff --git a/conf/machine/include/ibm.inc b/conf/machine/include/ibm.inc
new file mode 100644
index 0000000..c79ddd7
--- /dev/null
+++ b/conf/machine/include/ibm.inc
@@ -0,0 +1 @@
+require conf/machine/include/openpower.inc