asoc: codecs: Add mutex lock for CPE session

Add mutex lock to ensure atomic access to core handle
in CPE alloc and dealloc sessions.

CRs-Fixed: 2169403
Change-Id: I7e046f349cc56ee06706cf15651dac3fdfe9d9a6
Signed-off-by: Vaishnavi Kommaraju <vkommara@codeaurora.org>

asoc/codecs/wcd_cpe_services.c

@@ -1,4 +1,4 @@
-/* Copyright (c) 2014-2017, The Linux Foundation. All rights reserved.
+/* Copyright (c) 2014-2018, 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
@@ -606,8 +606,10 @@ static enum cpe_svc_result cpe_deregister_generic(struct cpe_info *t_info,
 		return CPE_SVC_INVALID_HANDLE;
 	}
 
+	CPE_SVC_GRAB_LOCK(&cpe_d.cpe_svc_lock, "cpe_svc");
 	list_del(&(n->list));
 	kfree(reg_handle);
+	CPE_SVC_REL_LOCK(&cpe_d.cpe_svc_lock, "cpe_svc");
 
 	return CPE_SVC_SUCCESS;
 }