powerpc/85xx: fix null pointer dereference when init the SGMII TBI PHY

Function dtsec_configure_serdes() needs to know where the TBI PHY registers
are in order to configure SGMII for proper SerDes operation.

During SGMII initialzation, fm_eth_init_mac() passing NULL for 'phyregs'
when it called init_dtsec(), because it was believed that phyregs was not
used.  In fact, it is used by dtsec_configure_serdes() to configure the TBI
PHY registers.

We also need to define the PHY registers in struct fm_mdio.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
diff --git a/drivers/net/fm/dtsec.c b/drivers/net/fm/dtsec.c
index a77ee20..7dd78f2 100644
--- a/drivers/net/fm/dtsec.c
+++ b/drivers/net/fm/dtsec.c
@@ -171,7 +171,7 @@
 		void *phyregs, int max_rx_len)
 {
 	mac->base = base;
-	mac->phyregs = NULL;
+	mac->phyregs = phyregs;
 	mac->max_rx_len = max_rx_len;
 	mac->init_mac = dtsec_init_mac;
 	mac->enable_mac = dtsec_enable_mac;