dt-bindings: qcom,pdc: Add missing compatibles

Document the compatibles that are already in use in the upstream Linux
kernel to resolve dtbs_check warnings.

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20221013091208.356739-1-luca.weiss@fairphone.com


Signed-off-by: Rob Herring <robh@kernel.org>