net: dsa: allow switch drivers to specify phy_device::dev_flags

Some switch drivers (e.g: bcm_sf2) may have to communicate specific
workarounds or flags towards the PHY device driver. Allow switches
driver to be delegated that task by introducing a get_phy_flags()
callback which will do just that.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/dsa.h b/include/net/dsa.h
index c779e9b..e020b8a 100644
--- a/include/net/dsa.h
+++ b/include/net/dsa.h
@@ -181,6 +181,7 @@
 	char	*(*probe)(struct device *host_dev, int sw_addr);
 	int	(*setup)(struct dsa_switch *ds);
 	int	(*set_addr)(struct dsa_switch *ds, u8 *addr);
+	u32	(*get_phy_flags)(struct dsa_switch *ds, int port);
 
 	/*
 	 * Access to the switch's PHY registers.