coresight: etm3x: adding cpu affinity to sysFS interface

Without access to the device tree, it is impossible to know
what CPU a tracer is affined to.  As such adding a new sysFS
interface to convey the information.

Change-Id: I19d75aa8f8942330691294453c6b75c7d05c145f
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: adfad8745c38d2bfe9e855f9d112a8583564112f
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


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