Since unit addresses are passed to simple-audio-card,dai-link a
corresponding 'reg' property is needed, otherwise dtc complains
(when building with W=1) in case someone copies the bindings example
into a real dts file:

Warning (unit_address_vs_reg): Node /sound-digital/simple-audio-card,dai-link@0 has a unit name, but no reg property

Improve the example by passing the correct 'reg' properties.
Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>