cereal: set PV

OE norms dictate that recipes using the git fetcher set PV explicitly
to "x.y.z+git${SRCPV}"

Tested: Built the cereal recipe
Change-Id: Ib4206b85691e95e0157704c9bd196bc44964c64f
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/common/recipes-support/serialization/cereal_1.2.2.bb b/common/recipes-support/serialization/cereal_1.2.2.bb
index 9b60187..50c8578 100644
--- a/common/recipes-support/serialization/cereal_1.2.2.bb
+++ b/common/recipes-support/serialization/cereal_1.2.2.bb
@@ -8,6 +8,7 @@
 
 SRC_URI += "git://github.com/USCiLab/cereal"
 SRCREV = "51cbda5f30e56c801c07fe3d3aba5d7fb9e6cca4"
+PV = "1.2.2+git${SRCPV}"
 
 S = "${WORKDIR}/git"