This driver adds support for the STM CoreSight IP block, allowing any
system compoment (HW or SW) to log and aggregate messages via a
single entity.

The CoreSight STM exposes an application defined number of channels
called stimulus port.  Configuration is done using entries in sysfs
and channels made available to userspace via configfs.
Signed-off-by: NPratik Patel <pratikp@codeaurora.org>
Signed-off-by: NMathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: NMichael Williams <michael.williams@arm.com>
Signed-off-by: NChunyan Zhang <zhang.chunyan@linaro.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>