Disable the MDIO interrupt, falling back to polled mode, if the resource
size does not allow us to access the interrupt registers.  All current
DT bindings use a size of 0x84, which allows access, but verifying it is
good practice.
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>