net: dsa: bcm_sf2: Only 7278 supports 2Gb/sec IMP port

The 7445 switch clocking profiles do not allow us to run the IMP port at
2Gb/sec in a way that it is reliable and consistent. Make sure that the
setting is only applied to the 7278 family.

Fixes: 8f1880cb ("net: dsa: bcm_sf2: Configure IMP port for 2Gb/sec")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/bcm_sf2.c

@@ -68,7 +68,9 @@ static void bcm_sf2_imp_setup(struct dsa_switch *ds, int port)
 
 		/* Force link status for IMP port */
 		reg = core_readl(priv, offset);
-		reg |= (MII_SW_OR | LINK_STS | GMII_SPEED_UP_2G);
+		reg |= (MII_SW_OR | LINK_STS);
+		if (priv->type == BCM7278_DEVICE_ID)
+			reg |= GMII_SPEED_UP_2G;
 		core_writel(priv, reg, offset);
 
 		/* Enable Broadcast, Multicast, Unicast forwarding to IMP port */