mips: dts: ralink: mt7621: change mt7530 switch address

In the case of muxing phy0 of the MT7530 switch, the switch and the phy
will have the same address on the mdio bus, 0. This causes the ethernet
driver to fail since devices on the mdio bus cannot share an address.

Any address can be used for the switch, therefore, change the switch
address to 0x1f.

Suggested-by: Sungbo Eo <mans0n@gorani.run>
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Reviewed-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>