lan743x: Remove phy_read from link status change function

It has been noticed that some phys do not have the registers
required by the previous implementation.

To fix this, instead of using phy_read, the required information
is extracted from the phy_device structure.

fixes: 23f0703c ("lan743x: Add main source files for new lan743x driver")
Signed-off-by: Bryan Whitehead <Bryan.Whitehead@microchip.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>