Add strings with GPRS GMM messages

Change-Id: I48477b733e2da72f59349c00554dd3e080c9f445
Related: OS#1582
diff --git a/src/gsm/gsm_04_08_gprs.c b/src/gsm/gsm_04_08_gprs.c
index 7018777..7cfcc80 100644
--- a/src/gsm/gsm_04_08_gprs.c
+++ b/src/gsm/gsm_04_08_gprs.c
@@ -137,6 +137,30 @@
 	}
 }
 
+const struct value_string gprs_msgt_gmm_names[] = {
+	{ GSM48_MT_GMM_ATTACH_REQ,		"ATTACH REQUEST" },
+	{ GSM48_MT_GMM_ATTACH_ACK,		"ATTACH ACK" },
+	{ GSM48_MT_GMM_ATTACH_COMPL,		"ATTACH COMPLETE" },
+	{ GSM48_MT_GMM_ATTACH_REJ,		"ATTACH REJECT" },
+	{ GSM48_MT_GMM_DETACH_REQ,		"DETACH REQUEST" },
+	{ GSM48_MT_GMM_DETACH_ACK,		"DETACH ACK" },
+	{ GSM48_MT_GMM_RA_UPD_REQ,		"RA UPDATE REQUEST" },
+	{ GSM48_MT_GMM_RA_UPD_ACK,		"RA UPDATE ACK" },
+	{ GSM48_MT_GMM_RA_UPD_COMPL,		"RA UPDATE COMPLETE" },
+	{ GSM48_MT_GMM_RA_UPD_REJ,		"RA UPDATE REJECT" },
+	{ GSM48_MT_GMM_PTMSI_REALL_CMD,		"PTMSI REALLOC CMD" },
+	{ GSM48_MT_GMM_PTMSI_REALL_COMPL,	"PTMSI REALLOC COMPLETE" },
+	{ GSM48_MT_GMM_AUTH_CIPH_REQ,		"AUTH & CIPHER REQUEST" },
+	{ GSM48_MT_GMM_AUTH_CIPH_RESP,		"AUTH & CIPHER RESPONSE" },
+	{ GSM48_MT_GMM_AUTH_CIPH_REJ,		"AUTH & CIPHER REJECT" },
+	{ GSM48_MT_GMM_AUTH_CIPH_FAIL,		"AUTH & CIPHER FAILURE" },
+	{ GSM48_MT_GMM_ID_REQ,			"IDENTITY REQUEST" },
+	{ GSM48_MT_GMM_ID_RESP,			"IDENTITY RESPONSE" },
+	{ GSM48_MT_GMM_STATUS,			"STATUS" },
+	{ GSM48_MT_GMM_INFO,			"INFO" },
+	{ 0, NULL }
+};
+
 /* 10.5.5.2 */
 const struct value_string gprs_att_t_strs_[] = {
 	{ GPRS_ATT_T_ATTACH,		"GPRS attach" },