net: tcp2: Fix mbedtls missing warnings

If CONFIG_NET_TCP_ISN_RFC6528 is disabled, then mbedtls include
files are not available so check this.

Signed-off-by: Jukka Rissanen <[email protected]>

Author: jukkar

subsys/net/ip/tcp2.c

@@ -12,7 +12,10 @@ LOG_MODULE_REGISTER(net_tcp, CONFIG_NET_TCP_LOG_LEVEL);
 #include <stdlib.h>
 #include <zephyr.h>
 #include <random/rand32.h>
+
+#if defined(CONFIG_NET_TCP_ISN_RFC6528)
 #include <mbedtls/md5.h>
+#endif
 #include <net/net_pkt.h>
 #include <net/net_context.h>
 #include <net/udp.h>
@@ -1313,7 +1316,10 @@ static uint32_t tcpv6_init_isn(struct in6_addr *saddr,
 	}
 
 	memcpy(buf.key, unique_key, sizeof(buf.key));
+
+#if IS_ENABLED(CONFIG_NET_TCP_ISN_RFC6528)
 	mbedtls_md5_ret((const unsigned char *)&buf, sizeof(buf), hash);
+#endif
 
 	return seq_scale(UNALIGNED_GET((uint32_t *)&hash[0]));
 }
@@ -1345,7 +1351,10 @@ static uint32_t tcpv4_init_isn(struct in_addr *saddr,
 	}
 
 	memcpy(buf.key, unique_key, sizeof(unique_key));
+
+#if IS_ENABLED(CONFIG_NET_TCP_ISN_RFC6528)
 	mbedtls_md5_ret((const unsigned char *)&buf, sizeof(buf), hash);
+#endif
 
 	return seq_scale(UNALIGNED_GET((uint32_t *)&hash[0]));
 }