coresight: bindings for coresight drivers

Coresight IP blocks allow for the support of HW assisted tracing
on ARM SoCs.  Bindings for the currently available blocks are
presented herein.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>