dt-bindings: remoteproc: qcom,pil-info: add missing imem compatible

syscon and simple-mfd cannot be used without device specific compatible.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20220817142246.828762-4-krzysztof.kozlowski@linaro.org


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