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/scripts/yocto-check-layer b/poky/scripts/yocto-check-layer
index 5a4fd75..9b7e536 100755
--- a/poky/scripts/yocto-check-layer
+++ b/poky/scripts/yocto-check-layer
@@ -169,7 +169,14 @@
         td['bbvars'] = get_bb_vars()
         logger.info('Getting initial signatures ...')
         td['builddir'] = builddir
-        td['sigs'], td['tunetasks'] = get_signatures(td['builddir'])
+        try:
+            td['sigs'], td['tunetasks'] = get_signatures(td['builddir'])
+        except RuntimeError as e:
+            logger.info(str(e))
+            results[layer['name']] = None
+            results_status[layer['name']] = 'FAIL (Generating world signatures)'
+            layers_tested = layers_tested + 1
+            continue
         td['machines'] = args.machines
 
         if not add_layer(bblayersconf, layer, dep_layers, logger):