Rename write signature algorithms function

To keep similar name with other place.

Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>
diff --git a/library/ssl_misc.h b/library/ssl_misc.h
index 50aee6f..6b0bf57 100644
--- a/library/ssl_misc.h
+++ b/library/ssl_misc.h
@@ -1435,10 +1435,10 @@
 /*
  * Write TLS1.3 Signature Algorithm extesion
  */
-int mbedtls_ssl_tls13_write_signature_algorithms_ext( mbedtls_ssl_context *ssl,
-                                                      unsigned char *buf,
-                                                      unsigned char *end,
-                                                      size_t *olen);
+int mbedtls_ssl_tls13_write_sig_alg_ext( mbedtls_ssl_context *ssl,
+                                         unsigned char *buf,
+                                         unsigned char *end,
+                                         size_t *olen);
 #endif /* MBEDTLS_KEY_EXCHANGE_WITH_CERT_ENABLED */
 
 #endif /* MBEDTLS_SSL_PROTO_TLS1_3_EXPERIMENTAL */