arm: am335x: DXR2: Reset SMSC LAN9303 switch via GPIO upon bootup

Since the switch may be re-configured for VLAN usage in Linux (or any
other OS), lets reset the switch to its default register values upon
power-up. Otherwise network might not be available in U-Boot.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Roger Meier <r.meier@siemens.com>
Cc: Lukas Stockmann <lukas.stockmann@siemens.com>
Cc: Tom Rini <trini@ti.com>
diff --git a/include/configs/dxr2.h b/include/configs/dxr2.h
index e95d74c..75f7812 100644
--- a/include/configs/dxr2.h
+++ b/include/configs/dxr2.h
@@ -26,6 +26,7 @@
 
 #define BOARD_DFU_BUTTON_GPIO	27
 #define BOARD_DFU_BUTTON_LED	64
+#define GPIO_LAN9303_NRST	88	/* GPIO2_24 = gpio88 */
 
 #undef CONFIG_DOS_PARTITION
 #undef CONFIG_CMD_FAT