arm: dts: mt2701: Add reset-cells

commit ae72e95b5e4ded145bfc6926ad9457b74e3af41a upstream.

The hifsys and ethsys needs the definition of the reset-cells
property. Fix this.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>