Refine code base on review

Remove useless hrr code
Share validate_cipher_suit between client and server
Fix test failure when tls13 only in server side

Change-Id: I5d6a7932bd8448ebf542bc86cdcab8862bc28e9b
Signed-off-by: XiaokangQian <xiaokang.qian@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 025732e..d276082 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -589,6 +589,8 @@
 #if defined(MBEDTLS_SSL_SRV_C)
     /** selected_group of key_share extension in HelloRetryRequest message. */
     uint16_t hrr_selected_group;
+    /** selected_group of key_share extension in ClientHello message. */
+    uint16_t selected_group;
 #endif /* MBEDTLS_SSL_SRV_C */
 
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \