cryptodev: 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: 7a33572057 ("lib: remove C++ include guard from private headers")
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/cryptodev/cryptodev_pmd.h

@@ -5,6 +5,10 @@
 #ifndef _CRYPTODEV_PMD_H_
 #define _CRYPTODEV_PMD_H_
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 /** @file
  * RTE Crypto PMD APIs
  *
@@ -636,4 +640,8 @@ RTE_STD_C11 struct rte_cryptodev_asym_session {
 	uint8_t sess_private_data[0];
 };
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif /* _CRYPTODEV_PMD_H_ */