dt-bindings: arm: Add support for Coresight dummy trace

This patch add support for Coresight dummy source and dummy sink trace.

Signed-off-by: Hao Zhang <quic_hazha@quicinc.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230602084149.40031-3-quic_hazha@quicinc.com