coresight: etm3x: adding operation mode for etm_enable()

coresight: etm3x: adding operation mode for etm_enable()

Adding a new mode to source API enable() in order to
distinguish where the request comes from.  That way it is
possible to perform different operations based on where
the request was issued from.

The ETM4x driver is also modified to keep in sync with the
new interface.

Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit 22fd532eaa0c24d86e23d8e9e3b7feac4a8cac80)