ASoC: Intel, Keembay-i2s: Add hdmi-i2s compatible string

Add intel,keembay-hdmi-i2s compatible string to support the
HDMI interface.
Signed-off-by: Sia Jee Heng <jee.heng.sia@intel.com>
Link: https://lore.kernel.org/r/20210204014258.10197-4-jee.heng.sia@intel.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/intel,keembay-i2s.yaml

@@ -18,6 +18,7 @@ properties:
     enum:
       - intel,keembay-i2s
       - intel,keembay-tdm
+      - intel,keembay-hdmi-i2s
 
   "#sound-dai-cells":
     const: 0