components/openssl: optimize the SSL certification and private key function

1. add inheritance function
2. remove low-level platform unload cert & pkey function
3. optimize the cert load and free function

components/openssl/include/internal/ssl_cert.h

@@ -21,6 +21,15 @@
 
 #include "ssl_types.h"
 
+/**
+ * @brief create a certification object include private key object according to input certification
+ *
+ * @param ic - input certification point
+ *
+ * @return certification object point
+ */
+CERT *__ssl_cert_new(CERT *ic);
+
 /**
  * @brief create a certification object include private key object
  *