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

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>

(Upstream commit ec13c78d7b45851d21786127ae17193f9a1446fb).

Bug: 140266694
Change-Id: If19ed31b5c2b89a62fb4bfddb95f7e3725c7d91d
Signed-off-by: Yabin Cui <yabinc@google.com>