dt-bindings: dmaengine: bam_dma: add remote controlled bindings

This patch adds 2 new properties for remote controlled bam dt bindings.
1. num-channels to indicate number of dma channels.
2. qcom,num-ees to indicate number of Execution Environments.

Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>