broadband-modem-mbim: MbimSmsStatusFlag is flags, not an enum

We can directly use this change instead of requiring the libmbim
version bump because the numeric values of the enum didn't change:
  NEW_MESSAGE == 2 == (1<<1)

Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/673

src/mm-broadband-modem-mbim.c

@@ -5127,7 +5127,7 @@ sms_notification (MMBroadbandModemMbim *self,
                 &index,
                 NULL)) {
             mm_obj_dbg (self, "received SMS store status update: '%s'", mbim_sms_status_flag_get_string (flag));
-            if (flag == MBIM_SMS_STATUS_FLAG_NEW_MESSAGE)
+            if (flag & MBIM_SMS_STATUS_FLAG_NEW_MESSAGE)
                 sms_notification_read_stored_sms (self, index);
         }
         break;