coresight: fixing typographical error

Tracing gets enabled _for_ a source rather than _from_ a source.

Change-Id: Id85f91e7215278d46d48224d9fbce0c1d086b0fa
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 1d27ff5aba2d36b152542e9d62158eb6584bcbd3
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


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