coresight-etm3x: Support context-ID tracing when PID namespace is enabled

The Coresight ETM drivers already support context-ID tracing, but it won't
work when PID namespace is enabled. This is because when using PID
namespace a process id (ie. VPID) seen from the current namespace differs
from the id (ie. PID) seen by kernel.

So when users write the process id seen by themselves to ETM, there needs
to be a translation from VPID to PID, as such ETM drivers will write the
PID into the Context ID register correctly.

Change-Id: I29727270dd28b8812ffe7b7d2d22dc60f4acb2a9
Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: a440617e0d882a35accdd32dd7ae180885c6b28c
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Shashank Mittal <mittals@codeaurora.org>