libosmocore: Upgrade for the tlvp_val16.. code

This code has an ABI incompatible change, bump the meta-telephony
version to force a rebuild of downstream.
diff --git a/conf/layer.conf b/conf/layer.conf
index 145b809..f208e42 100644
--- a/conf/layer.conf
+++ b/conf/layer.conf
@@ -9,4 +9,4 @@
 BBFILE_PATTERN_telephony := "^${LAYERDIR}/"
 BBFILE_PRIORITY_telephony = "5"
 
-META_TELEPHONY_OSMO_INC = "7"
+META_TELEPHONY_OSMO_INC = "8"