reset upstream subtrees to HEAD

Reset the following subtrees on HEAD:
  poky: 8217b477a1(master)
  meta-xilinx: 64aa3d35ae(master)
  meta-openembedded: 0435c9e193(master)
  meta-raspberrypi: 490a4441ac(master)
  meta-security: cb6d1c85ee(master)

Squashed patches:
  meta-phosphor: drop systemd 239 patches
  meta-phosphor: mrw-api: use correct install path

Change-Id: I268e2646d9174ad305630c6bbd3fbc1a6105f43d
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/poky/meta-poky/README.poky b/poky/meta-poky/README.poky
index 0a42843..2204801 100644
--- a/poky/meta-poky/README.poky
+++ b/poky/meta-poky/README.poky
@@ -27,6 +27,19 @@
 For information about OpenEmbedded, see the OpenEmbedded website:
     http://www.openembedded.org/
 
+
+Contribution Guidelines
+=======================
+
+A guide to submitting patches to OpenEmbedded is available at:
+
+http://www.openembedded.org/wiki/How_to_submit_a_patch_to_OpenEmbedded
+
+There is good documentation on how to write/format patches at:
+
+https://www.openembedded.org/wiki/Commit_Patch_Message_Guidelines
+
+
 Where to Send Patches
 =====================