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/common/recipes-devtools/gcc/gcc-source_6.3.bbappend b/common/recipes-devtools/gcc/gcc-source_6.3.bbappend
new file mode 100644
index 0000000..2fadb55
--- /dev/null
+++ b/common/recipes-devtools/gcc/gcc-source_6.3.bbappend
@@ -0,0 +1,2 @@
+FILESEXTRAPATHS_append := "${THISDIR}/gcc_6.3:"
+SRC_URI_append = "file://0001-Support-exception-propagation-without-lock-free-atom.patch"