[PATCH 5/6] mvneta: implement SGMII-based in-band link state signaling

When MDIO bus is unavailable (common setup for SGMII), the in-band signaling must be used to correctly track link state. This patch enables the in-band status delivery and interrupts for links state changes, namely: - link up/down - link speed - duplex full/half Upon reciving the appropriate

[PATCH 5/6] mvneta: implement SGMII-based in-band link state signaling

When MDIO bus is unavailable (common setup for SGMII), the in-band signaling must be used to correctly track link state. This patch enables the in-band status delivery and interrupts for links state changes, namely: - link up/down - link speed - duplex full/half Upon reciving the appropriate