board: amlogic: Generate unique MAC address for Q200 and P212 based boards

Enable unique MAC address generation for boards usins SoCs having
a known functional and valid unique serial number.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
diff --git a/board/amlogic/p212/p212.c b/board/amlogic/p212/p212.c
index 546c4d9..1159cee 100644
--- a/board/amlogic/p212/p212.c
+++ b/board/amlogic/p212/p212.c
@@ -32,6 +32,8 @@
 					  mac_addr, EFUSE_MAC_SIZE);
 		if (len == EFUSE_MAC_SIZE && is_valid_ethaddr(mac_addr))
 			eth_env_set_enetaddr("ethaddr", mac_addr);
+		else
+			meson_generate_serial_ethaddr();
 	}
 
 	if (!env_get("serial#")) {