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/bitbake/LICENSE b/import-layers/yocto-poky/bitbake/LICENSE
index 5d4a4c2..7d4e5f4 100644
--- a/import-layers/yocto-poky/bitbake/LICENSE
+++ b/import-layers/yocto-poky/bitbake/LICENSE
@@ -15,3 +15,5 @@
 * QUnit is redistributed under the MIT license.
 
 * Font Awesome fonts redistributed under the SIL Open Font License 1.1
+
+* simplediff is distributed under the zlib license.