phy: Add media type and speed serdes configuration interfaces

Provide new phy configuration interfaces for media type and speed that
allows e.g. PHYs used for ethernet to be configured with this
information.

Signed-off-by: Lars Povlsen <lars.povlsen@microchip.com>
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-By: Kishon Vijay Abraham I <kishon@ti.com>
Link: https://lore.kernel.org/r/20210218161451.3489955-3-steen.hegelund@microchip.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>