Removes truncated HMAC code from ssl.h

Commit removes conditionally compiled code
relating to MBEDTLS_SSL_TRUNCATED_HMAC from
ssl.h.

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index b2f5c67..a93a325 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -956,10 +956,6 @@
     unsigned char MBEDTLS_PRIVATE(mfl_code);     /*!< MaxFragmentLength negotiated by peer */
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
-#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
-    int MBEDTLS_PRIVATE(trunc_hmac);             /*!< flag for truncated hmac activation   */
-#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
-
 #if defined(MBEDTLS_SSL_ENCRYPT_THEN_MAC)
     int MBEDTLS_PRIVATE(encrypt_then_mac);       /*!< flag for EtM activation                */
 #endif
@@ -1180,9 +1176,6 @@
 #if defined(MBEDTLS_SSL_RENEGOTIATION)
     unsigned int MBEDTLS_PRIVATE(disable_renegotiation) : 1; /*!< disable renegotiation?     */
 #endif
-#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
-    unsigned int MBEDTLS_PRIVATE(trunc_hmac) : 1;    /*!< negotiate truncated hmac?          */
-#endif
 #if defined(MBEDTLS_SSL_SESSION_TICKETS)
     unsigned int MBEDTLS_PRIVATE(session_tickets) : 1;   /*!< use session tickets?           */
 #endif
@@ -3315,18 +3308,6 @@
 void mbedtls_ssl_conf_preference_order( mbedtls_ssl_config *conf, int order );
 #endif /* MBEDTLS_SSL_SRV_C */
 
-#if defined(MBEDTLS_SSL_TRUNCATED_HMAC)
-/**
- * \brief          Activate negotiation of truncated HMAC
- *                 (Default: MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
- *
- * \param conf     SSL configuration
- * \param truncate Enable or disable (MBEDTLS_SSL_TRUNC_HMAC_ENABLED or
- *                                    MBEDTLS_SSL_TRUNC_HMAC_DISABLED)
- */
-void mbedtls_ssl_conf_truncated_hmac( mbedtls_ssl_config *conf, int truncate );
-#endif /* MBEDTLS_SSL_TRUNCATED_HMAC */
-
 #if defined(MBEDTLS_SSL_SESSION_TICKETS) && defined(MBEDTLS_SSL_CLI_C)
 /**
  * \brief          Enable / Disable session tickets (client only).