ASoC: dt-bindings: keembay-i2s: Fix reg descriptions

ASoC: dt-bindings: keembay-i2s: Fix reg descriptions

intel,keembay-i2s has two register regions:
- I2S registers
- I2S gen configuration

Describe these regions accordingly to fix the following warning seen
with 'make dt_binding_check':

Documentation/devicetree/bindings/sound/intel,keembay-i2s.example.dt.yaml: example-0: i2s@20140000:reg:0: [538181632, 512, 539623588, 4] is too long

Signed-off-by: Fabio Estevam <festevam@gmail.com>
Link: https://lore.kernel.org/r/20200630224459.27174-1-festevam@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>