ASoC: Add compatible strings for JZ4760(B) SoC

Add the ingenic,jz4760b-codec and ingenic,jz4760-codec compatible
strings.

In the process, convert the previous compatible strings to use an enum
instead.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20210123140958.12895-1-paul@crapouillou.net
Signed-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/ingenic,codec.yaml

@@ -15,9 +15,14 @@ properties:
 
   compatible:
     oneOf:
-      - const: ingenic,jz4770-codec
-      - const: ingenic,jz4725b-codec
-      - const: ingenic,jz4740-codec
+      - enum:
+          - ingenic,jz4770-codec
+          - ingenic,jz4760-codec
+          - ingenic,jz4725b-codec
+          - ingenic,jz4740-codec
+      - items:
+          - const: ingenic,jz4760b-codec
+          - const: ingenic,jz4760-codec
 
   reg:
     maxItems: 1