board: s400: generate unique mac address from SoC serial

Enable unique mac address generation from SoC serial on S400 board.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/board/amlogic/s400/s400.c b/board/amlogic/s400/s400.c
index 7e2f0cd..b081942 100644
--- a/board/amlogic/s400/s400.c
+++ b/board/amlogic/s400/s400.c
@@ -18,5 +18,7 @@
 {
 	meson_eth_init(PHY_INTERFACE_MODE_RGMII, 0);
 
+	meson_generate_serial_ethaddr();
+
 	return 0;
 }