dt-bindings: dmaengine: bam_dma: Add "powered remotely" mode

In some configurations, the BAM DMA controller is set up by a remote
processor and the local processor can simply start making use of it
without setting up the BAM. This is already supported using the
"qcom,controlled-remotely" property.

However, for some reason another possible configuration is that the
remote processor is responsible for powering up the BAM, but we are
still responsible for initializing it (e.g. resetting it etc). Add
a "qcom,powered-remotely" property to describe that configuration.

Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Link: https://lore.kernel.org/r/20211018102421.19848-2-stephan@gerhold.net
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Documentation/devicetree/bindings/dma/qcom_bam_dma.txt

@@ -15,6 +15,8 @@ Required properties:
   the secure world.
 - qcom,controlled-remotely : optional, indicates that the bam is controlled by
   remote proccessor i.e. execution environment.
+- qcom,powered-remotely : optional, indicates that the bam is powered up by
+  a remote processor but must be initialized by the local processor.
 - num-channels : optional, indicates supported number of DMA channels in a
   remotely controlled bam.
 - qcom,num-ees : optional, indicates supported number of Execution Environments