ASoC: dt-bindings: rt1015p: fix syntax error in dts-binding document

Fix syntax error in dts-binding document.
Signed-off-by: Jack Yu <jack.yu@realtek.com>
Fixes: 064478e4 ("ASoC: dt-bindings: rt1015p: add new compatible id")
Link: https://lore.kernel.org/r/20210810020834.32414-1-jack.yu@realtek.comSigned-off-by: Mark Brown <broonie@kernel.org>

Documentation/devicetree/bindings/sound/realtek,rt1015p.yaml

@@ -16,8 +16,8 @@ description: |
 properties:
   compatible:
       oneOf:
-        const: realtek,rt1015p
-        const: realtek,rt1019p
+        - const: realtek,rt1015p
+        - const: realtek,rt1019p
 
   sdb-gpios:
     description: