net: phy: meson-gxl: use genphy_config_init

Use the generic init function to populate some of the phydev
structure fields

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>