reset upstream subtrees to yocto 2.6

Reset the following subtrees on thud HEAD:

  poky: 87e3a9739d
  meta-openembedded: 6094ae18c8
  meta-security: 31dc4e7532
  meta-raspberrypi: a48743dc36
  meta-xilinx: c42016e2e6

Also re-apply backports that didn't make it into thud:
  poky:
    17726d0 systemd-systemctl-native: handle Install wildcards

  meta-openembedded:
    4321a5d libtinyxml2: update to 7.0.1
    042f0a3 libcereal: Add native and nativesdk classes
    e23284f libcereal: Allow empty package
    030e8d4 rsyslog: curl-less build with fmhttp PACKAGECONFIG
    179a1b9 gtest: update to 1.8.1

Squashed OpenBMC subtree compatibility updates:
  meta-aspeed:
    Brad Bishop (1):
          aspeed: add yocto 2.6 compatibility

  meta-ibm:
    Brad Bishop (1):
          ibm: prepare for yocto 2.6

  meta-ingrasys:
    Brad Bishop (1):
          ingrasys: set layer compatibility to yocto 2.6

  meta-openpower:
    Brad Bishop (1):
          openpower: set layer compatibility to yocto 2.6

  meta-phosphor:
    Brad Bishop (3):
          phosphor: set layer compatibility to thud
          phosphor: libgpg-error: drop patches
          phosphor: react to fitimage artifact rename

    Ed Tanous (4):
          Dropbear: upgrade options for latest upgrade
          yocto2.6: update openssl options
          busybox: remove upstream watchdog patch
          systemd: Rebase CONFIG_CGROUP_BPF patch

Change-Id: I7b1fe71cca880d0372a82d94b5fd785323e3a9e7
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/poky/documentation/Makefile b/poky/documentation/Makefile
index e41d5a0..093422f 100644
--- a/poky/documentation/Makefile
+++ b/poky/documentation/Makefile
@@ -165,6 +165,7 @@
 TARFILES = dev-style.css dev-manual.html figures/buildhistory-web.png \
            figures/dev-title.png figures/buildhistory.png \
            figures/recipe-workflow.png figures/bitbake-build-flow.png \
+           figures/multiconfig_files.png \
            eclipse
 	endif
 
@@ -261,7 +262,7 @@
         figures/image-generation.png figures/key-dev-elements.png\
 	figures/sdk-generation.png figures/recipe-workflow.png \
 	figures/build-workspace-directory.png figures/mega-title.png \
-	figures/toaster-title.png figures/hosted-service.png \
+	figures/toaster-title.png figures/hosted-service.png figures/multiconfig_files.png \
 	figures/simple-configuration.png figures/poky-reference-distribution.png \
 	figures/compatible-layers.png figures/import-layer.png figures/new-project.png \
 	figures/sdk-environment.png figures/sdk-installed-standard-sdk-directory.png \