Documentation: devicetree: Add PHY no lane swap binding

Add the documentation to avoid PHY lane swapping. This is a boolean
entry to notify the phy device drivers that the TX/RX lanes NO need
to be swapped.
The use case for this binding mostly happens after wrong HW
configuration of PHY IC during bootstrap.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>