lib: processor: add ceva support

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

lib/processor/ceva/CMakeLists.txt

@@ -0,0 +1,3 @@
+collect (PROJECT_LIB_HEADERS cpu.h)
+
+# vim: expandtab:ts=2:sw=2:smartindent

lib/processor/ceva/cpu.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2017, Pinecone Inc. and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+/*
+ * @file	cpu.h
+ * @brief	CPU specific primitives
+ */
+
+#ifndef __METAL_CEVA_CPU__H__
+#define __METAL_CEVA_CPU__H__
+
+#define metal_cpu_yield()
+
+#ifdef TEAKLITE4
+/*
+ * The dummy implementation is enough here since
+ * tl42x don't support the out of order and multi core
+ */
+#define __sync_synchronize()
+#endif
+
+#endif /* __METAL_CEVA_CPU__H__ */