net: phy: Add Amlogic Meson GXL Internal PHY support

The Amlogic Meson GXL/GXM families embeds an internal RMII Ethernet PHY.

The PHY acts as a generic PHY but needs a slight configuration right
before it's configuration.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>

include/phy.h

@@ -268,6 +268,7 @@ int phy_lxt_init(void);
 int phy_marvell_init(void);
 int phy_micrel_ksz8xxx_init(void);
 int phy_micrel_ksz90x1_init(void);
+int phy_meson_gxl_init(void);
 int phy_natsemi_init(void);
 int phy_realtek_init(void);
 int phy_smsc_init(void);