FROMLIST: coresight: tmc: implementing TMC-ETR AUX space API

This patch implement the AUX area interfaces required to
use the TMC (configured as an ETR) from the Perf sub-system.

The ETR is configured to work with contiguous memory only.
Although not optimal, it allows the IP block to be used
while the scatter-gather mode of operation is being worked
on.

The heuristic is heavily borrowed from the ETB10 and TMC-ETF
implementation.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
(cherry picked from commit ea817df0ff9e657c2bc1014787562dbf49bfdccd)

Change-Id: I6e5e28b63e6ffbfd0bde8db8c279206fec55ac5e