libosmocore: Upgrade to version 0.5.2 for the libgb split

libosmocore gained a new GPRS helper library.
diff --git a/recipes-osmocom/libosmocore/libosmocore_git.bb b/recipes-osmocom/libosmocore/libosmocore_git.bb
index cbe4295..ccc6999 100644
--- a/recipes-osmocom/libosmocore/libosmocore_git.bb
+++ b/recipes-osmocom/libosmocore/libosmocore_git.bb
@@ -1,7 +1,7 @@
 require ${PN}.inc
 
 S = "${WORKDIR}/git"
-SRCREV = "81cd54a0c36cd9cf2bedd97221658a276aa2d84c"
+SRCREV = "c5f055f9e5aa58548b484345bd3bdc914e640d6c"
 SRC_URI = "git://git.osmocom.org/libosmocore.git;protocol=git"
-PV = "0.4.1+gitr${SRCPV}"
+PV = "0.5.2+gitr${SRCPV}"
 PR = "0"