ASoC: rockchip: Drop unneeded properties rockchip i2s/spdif bindings

Neither the rockchip i2s nor the rockchip spdif binding support child
devices so #address-cells and #size-cells properties aren't required.
Remove these from the bindings.

Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>