TLS: Increase maximum MAC key from 20 to 32 octets

This is in prepartion of adding support for SHA256-based operations
with TLS v1.2.

Signed-hostap: Jouni Malinen <j@w1.fi>

src/tls/tlsv1_record.h

@@ -17,7 +17,7 @@
 
 #include "crypto/crypto.h"
 
-#define TLS_MAX_WRITE_MAC_SECRET_LEN 20
+#define TLS_MAX_WRITE_MAC_SECRET_LEN 32
 #define TLS_MAX_WRITE_KEY_LEN 32
 #define TLS_MAX_IV_LEN 16
 #define TLS_MAX_KEY_BLOCK_LEN (2 * (TLS_MAX_WRITE_MAC_SECRET_LEN + \