acl: add missing C++ guards

Some public header files were missing 'extern "C"' C++ guards,
and couldn't be used by C++ applications. Add the missing guards.

Fixes: dc276b5780c2 ("acl: new library")
Cc: stable@dpdk.org

Signed-off-by: Brian Dooley <brian.dooley@intel.com>
Acked-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Tyler Retzlaff <roretzla@linux.microsoft.com>

lib/acl/rte_acl_osdep.h

@@ -5,6 +5,10 @@
 #ifndef _RTE_ACL_OSDEP_H_
 #define _RTE_ACL_OSDEP_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /**
  * @file
  *
@@ -45,4 +49,8 @@
 #include <rte_cpuflags.h>
 #include <rte_debug.h>
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _RTE_ACL_OSDEP_H_ */