Documentation: net: phy: switch documentation to rst format

Switch phylib documentation to rst format.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Documentation/networking/index.rst

@@ -29,6 +29,7 @@ Contents:
    msg_zerocopy
    failover
    net_failover
+   phy
    alias
    bridge
    snmp_counter