Update buildroot to 2015.05 base

Adds petitboot to openpower overlay rather rather than in buildroot branch.

Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>
diff --git a/openpower/package/petitboot/kexec-restart b/openpower/package/petitboot/kexec-restart
new file mode 100755
index 0000000..0175e76
--- /dev/null
+++ b/openpower/package/petitboot/kexec-restart
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+/usr/sbin/kexec -f -e
+
+while :
+do
+    sleep 1
+done