board: amlogic: add meson_generate_serial_ethaddr fallback to p200

Add a fall-back method to generate ethaddr from CPU serial on p200 boards
if the MAC cannot be read from efuse. This prevents random MAC addresses
on the WeTek Hub/Play2 boards.

Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
Link: https://lore.kernel.org/r/20240324151905.3817732-3-christianshewitt@gmail.com
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
diff --git a/board/amlogic/p200/p200.c b/board/amlogic/p200/p200.c
index 7c432f9..3061f7a 100644
--- a/board/amlogic/p200/p200.c
+++ b/board/amlogic/p200/p200.c
@@ -30,6 +30,8 @@
 					  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#")) {