UPSTREAM: coresight: perf: Clean up function etm_setup_aux()

(Upstream commit 02d5c897a091f8e064f022a5383978182751d7fb).

There is no point in allocating sink memory for a trace session if
there is not a way to free it once it is no longer needed.  As such make
sure the sink API function to allocate and free memory have been
implemented before moving ahead with the establishment of a trace
session.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Tested-by: Leo Yan <leo.yan@linaro.org>
Tested-by: Robert Walker <robert.walker@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 140266694
Change-Id: Ibfb1d9f2c47e4fb47091b2d9f2ca4c43acb4eb27
Signed-off-by: Yabin Cui <yabinc@google.com>