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/kernel-dev/kernel-dev-common.xml b/poky/documentation/kernel-dev/kernel-dev-common.xml
index 4c6fc35..9052876 100644
--- a/poky/documentation/kernel-dev/kernel-dev-common.xml
+++ b/poky/documentation/kernel-dev/kernel-dev-common.xml
@@ -25,7 +25,7 @@
             Before you can do any kernel development, you need to be
             sure your build host is set up to use the Yocto Project.
             For information on how to get set up, see the
-            "<ulink url='&YOCTO_DOCS_DEV_URL;#setting-up-the-development-host-to-use-the-yocto-project'>Preparing the Build Host</ulink>"
+            "<ulink url='&YOCTO_DOCS_DEV_URL;#dev-preparing-the-build-host'>Preparing the Build Host</ulink>"
             section in the Yocto Project Development Tasks Manual.
             Part of preparing the system is creating a local Git
             repository of the