ipc: Add support for apr over rpmsg

Add support for apr communication over rpmsg to enable
inter processor comuunication b/w APPS and ADSP for
audio usecases.

Change-Id: I834ded7f1dd709e1d9e835b852c2edc25e8607e0
Signed-off-by: Shiv Maliyappanahalli <smaliyap@codeaurora.org>

ipc/apr.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2010-2014, 2016-2017 The Linux Foundation. All rights reserved.
+/* Copyright (c) 2010-2014, 2016-2018 The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
@@ -1133,6 +1133,7 @@ void __exit apr_exit(void)
 {
 	subsys_notif_deregister("apr_modem");
 	subsys_notif_deregister("apr_adsp");
+	apr_tal_exit();
 }
 module_exit(apr_exit);
 MODULE_DESCRIPTION("APR module");