Add switch case for '-c' in reference-ril

Currently reference-ril not handling the '-c' option
that RILD is sending as part of "RIL_Init" arguments and
due to that reference-ril initialisation failing for emulator.

To fix this add switch case statement to handle '-c' option.

Change-Id: Ia2430cb1df91b42d51af7bf820ff42b8ce2b5066

reference-ril/reference-ril.c

@@ -3350,7 +3350,7 @@ const RIL_RadioFunctions *RIL_Init(const struct RIL_Env *env, int argc, char **a
 
     s_rilenv = env;
 
-    while ( -1 != (opt = getopt(argc, argv, "p:d:s:"))) {
+    while ( -1 != (opt = getopt(argc, argv, "p:d:s:c:"))) {
         switch (opt) {
             case 'p':
                 s_port = atoi(optarg);
@@ -3372,6 +3372,10 @@ const RIL_RadioFunctions *RIL_Init(const struct RIL_Env *env, int argc, char **a
                 RLOGI("Opening socket %s\n", s_device_path);
             break;
 
+            case 'c':
+                RLOGI("Client id received %s\n", optarg);
+            break;
+
             default:
                 usage(argv[0]);
                 return NULL;