net/phy: Expose 100base-T capability only

I don't know the specific PHY model deployed on Firestone BMC, but
currently used one (PHY_ID_BCM54210E) isn't correct. BCM54210E
supports 1000base-T but the PHY on Firestone BMC shouldn't support
that mode as uboot uses 100base-T mode.

When exposing 1000base-T capability, the MAC is forced to have the
same mode though the PHY is working in 100base-T mode in fact. It
causes the mode mismatch between PHY/MAC and the ethernet network
doesn't work.

It's a temporary fix. After the PHY model is confirmed, we need
to enable the correct PHY driver instead current one for BCM54210E.

Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>

[Cyril]
The plot thickens, it does appear that this IS the correct PHY on
firestones. This patch is definitely required for networking to be
functional though.

Signed-off-by: Cyril Bur <cyrilbur@gmail.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>

drivers/net/phy/broadcom.c

@@ -608,7 +608,7 @@ static struct phy_driver broadcom_drivers[] = {
 	.phy_id		= PHY_ID_BCM54210E,
 	.phy_id_mask	= 0xfffffff0,
 	.name		= "Broadcom BCM54210E",
-	.features	= PHY_GBIT_FEATURES |
+	.features	= PHY_BASIC_FEATURES |
 			  SUPPORTED_Pause | SUPPORTED_Asym_Pause,
 	.flags		= PHY_HAS_MAGICANEG | PHY_HAS_INTERRUPT,
 	.config_init	= bcm54xx_config_init,