of: mdio: honor flags passed to of_phy_connect

Commit f9a8f83b ("net: phy: remove flags argument from phy_{attach,
connect, connect_direct}") removed the flags argument to the PHY library
calls to: phy_{attach,connect,connect_direct}.

Most Device Tree aware drivers call of_phy_connect() with the flag
argument set to 0, but some of them might want to set a different value
there in order for the PHY driver to key a specific behavior based on
the phy_device::phy_flags value.

Allow such drivers to set custom phy_flags as part of the
of_phy_connect() call since of_phy_connect() does start the PHY state
machine, it will call into the PHY driver config_init() callback which
is usually where a specific phy_flags value is important.

Fixes: f9a8f83b ("net: phy: remove flags argument from phy_{attach, connect, connect_direct}")
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>