UPSTREAM: coresight: tmc-etr: Add barrier packets when moving offset forward

(Upstream commit ec13c78d7b45851d21786127ae17193f9a1446fb).

This patch adds barrier packets in the trace stream when the offset in the
data buffer needs to be moved forward.  Otherwise the decoder isn't aware
of the break in the stream and can't synchronise itself with the trace
data.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Yabin Cui <yabinc@google.com>
Reviewed-by: Leo Yan <leo.yan@linaro.org>
Link: https://lore.kernel.org/r/20190829202842.580-18-mathieu.poirier@linaro.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 140266694
Change-Id: I3d89e6267d8ca2397391ded7647cc379cd90d8d0
Signed-off-by: Yabin Cui <yabinc@google.com>