tsec: Fix MDIO on devices with eTSEC2

The tsec driver was defining the default MDIO address as
the TSEC_BASE + 0x520, but on eTSEC2 controllers, the first
TSEC's registers are separated from the MDIO registers. Use
the existing MDIO_BASE_ADDR, instead.

Signed-off-by: Andy Fleming <afleming@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

include/tsec.h

@@ -25,7 +25,7 @@
 #define TSEC_SIZE 		0x01000
 #define TSEC_MDIO_OFFSET	0x01000
 
-#define CONFIG_SYS_MDIO_BASE_ADDR (TSEC_BASE_ADDR + 0x520)
+#define CONFIG_SYS_MDIO_BASE_ADDR (MDIO_BASE_ADDR + 0x520)
 
 #define DEFAULT_MII_NAME "FSL_MDIO"