gsm0480: handle GSM0480_OP_CODE_PROCESS_USS_DATA

Change-Id: I470290c2b544555e53cedd849b1d6a961db7b5a4
diff --git a/src/gsm/gsm0480.c b/src/gsm/gsm0480.c
index 4d87974..328a8c0 100644
--- a/src/gsm/gsm0480.c
+++ b/src/gsm/gsm0480.c
@@ -437,6 +437,11 @@
 						   length - offset - 3,
 						   req);
 			break;
+		case GSM0480_OP_CODE_PROCESS_USS_DATA:
+			rc = parse_process_uss_data(invoke_data + offset + 3,
+						    length - offset - 3,
+						    req);
+			break;
 		case GSM0480_OP_CODE_ACTIVATE_SS:
 		case GSM0480_OP_CODE_DEACTIVATE_SS:
 		case GSM0480_OP_CODE_INTERROGATE_SS: