board: sama5d4_xplained: Set mac address from eeprom

Add the code to set the ethernet mac address from eeprom by using
the common code from the common folder.

Signed-off-by: Wenyou Yang <wenyou.yang@microchip.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/board/atmel/sama5d4_xplained/sama5d4_xplained.c b/board/atmel/sama5d4_xplained/sama5d4_xplained.c
index 854afcb..248a31b 100644
--- a/board/atmel/sama5d4_xplained/sama5d4_xplained.c
+++ b/board/atmel/sama5d4_xplained/sama5d4_xplained.c
@@ -192,6 +192,18 @@
 }
 #endif
 
+#define AT24MAC_MAC_OFFSET	0x9a
+
+#ifdef CONFIG_MISC_INIT_R
+int misc_init_r(void)
+{
+#ifdef CONFIG_I2C_EEPROM
+	at91_set_ethaddr(AT24MAC_MAC_OFFSET);
+#endif
+	return 0;
+}
+#endif
+
 int board_init(void)
 {
 	/* adress of boot parameters */