AT91: fix EMAC gpio init in at91sam9260_devices.c

The AT91SAM9G20 BOOT ROM apparently initializes PA23 and PA24 to multi drive
(open drain). Revert this, if those pins are going to be used for MII.

Signed-off-by: Reinhard Meyer <u-boot@emk-elektronik.de>

arch/arm/cpu/arm926ejs/at91/at91sam9260_devices.c

@@ -204,6 +204,11 @@ void at91_macb_hw_init(void)
 #else
 	at91_set_b_periph(AT91_PIO_PORTA, 23, 0);	/* ETX2 */
 	at91_set_b_periph(AT91_PIO_PORTA, 24, 0);	/* ETX3 */
+#if defined(CONFIG_AT91SAM9G20)
+	/* 9G20 BOOT ROM initializes those pins to multi-drive, undo that */
+	at91_set_pio_multi_drive(AT91_PIO_PORTA, 23, 0);
+	at91_set_pio_multi_drive(AT91_PIO_PORTA, 24, 0);
+#endif
 #endif
 	at91_set_b_periph(AT91_PIO_PORTA, 22, 0);	/* ETXER */
 #endif