Add skeleton-rev class

Reduce the number of files to be updated after a
skeleton update from two to one.

Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/meta-phosphor/classes/skeleton-rev.bbclass b/meta-phosphor/classes/skeleton-rev.bbclass
new file mode 100644
index 0000000..93544de
--- /dev/null
+++ b/meta-phosphor/classes/skeleton-rev.bbclass
@@ -0,0 +1,2 @@
+SRCREV ?= "b4140b888f586c98c5d03893166c5074a98cf951"
+SKELETON_URI ?= "git://github.com/openbmc/skeleton"