LCLS: enc/dec entire parameter set instead of GCR

In 3GPP TS 48.008 the Global Call Reference IE is only used in HANDOVER
REQUEST (§3.2.1.8) and ASSIGNMENT REQUEST (§3.2.1.1) messages which
also include LCLS Config and CSC parameters. Hence, there's no point in
using GCR encode/decode functions alone.

Introduce gsm0808_dec_lcls() and gsm0808_enc_lcls() as trivial wrappers
on top of GCR enc/dec routines which are made static. Adjust tests
accordingly. Test output intentionally left unchanged.

Change-Id: Icfbb2404e1a1d500243e2071173299b557369335
diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index 90c2195..76b3fd0 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -220,8 +220,8 @@
 gsm0808_lcls_config_names;
 gsm0808_lcls_control_names;
 gsm0808_lcls_status_names;
-gsm0808_enc_gcr;
-gsm0808_dec_gcr;
+gsm0808_enc_lcls;
+gsm0808_dec_lcls;
 
 gsm29118_msgb_alloc;
 gsm29118_create_alert_req;