osmocom: Fix the license of the libraries

GPL is too unspecific, point to the right versions
diff --git a/recipes-osmocom/libosmocore/libosmocore.inc b/recipes-osmocom/libosmocore/libosmocore.inc
index 6e091ef..c0dba30 100644
--- a/recipes-osmocom/libosmocore/libosmocore.inc
+++ b/recipes-osmocom/libosmocore/libosmocore.inc
@@ -1,6 +1,6 @@
 DESCRITOPN = "An utility library for Open Source Mobile Communications"
 HOMEPAGE = "http://openbsc.gnumonks.org"
-LICENSE = "GPL"
+LICENSE = "GPLv2+"
 
 INC_PR="r1.${META_TELEPHONY_OSMO_INC}"