Yocto 2.3

Move OpenBMC to Yocto 2.3(pyro).

Tested: Built and verified Witherspoon and Palmetto images
Change-Id: I50744030e771f4850afc2a93a10d3507e76d36bc
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
Resolves: openbmc/openbmc#2461
diff --git a/import-layers/yocto-poky/scripts/gen-lockedsig-cache b/import-layers/yocto-poky/scripts/gen-lockedsig-cache
index 49de74e..6765891 100755
--- a/import-layers/yocto-poky/scripts/gen-lockedsig-cache
+++ b/import-layers/yocto-poky/scripts/gen-lockedsig-cache
@@ -62,7 +62,11 @@
         os.remove(dst)
     if (os.stat(src).st_dev == os.stat(destdir).st_dev):
         print('linking')
-        os.link(src, dst)
+        try:
+            os.link(src, dst)
+        except OSError as e:
+            print('hard linking failed, copying')
+            shutil.copyfile(src, dst)
     else:
         print('copying')
         shutil.copyfile(src, dst)