lantiq: dts: drop superfluous unit address

lantiq: dts: drop superfluous unit address

The cpu temperature driver has the register offset hardcode and doesn't
need a reg.

The mdio bus node is only used as a well known name and doesn't need a
reg or unit address.

syscon-reboot doesn't have a unit address or a reg either. The unit name
collides with reset-controller@10 anyway.

Signed-off-by: Mathias Kresin <dev@kresin.me>