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/S14silence-console b/openpower/package/petitboot/S14silence-console
new file mode 100755
index 0000000..6570200
--- /dev/null
+++ b/openpower/package/petitboot/S14silence-console
@@ -0,0 +1,9 @@
+#!/bin/sh
+
+case "$1" in
+    start)
+        echo 0 0 7 0 > /proc/sys/kernel/printk
+        ;;
+esac
+
+exit 0