dt-bindings: soc: qcom: add qcom,qcs615-imem compatible

Document qcom,qcs615-imem compatible. It has a child node for debugging
purposes.

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Lijuan Gao <quic_lijuang@quicinc.com>
Link: https://lore.kernel.org/r/20250526-add_qcs615_remoteproc_support-v4-2-06a7d8bed0b5@quicinc.com


Signed-off-by: Bjorn Andersson <andersson@kernel.org>