coresight: etm4x: Improve usability of sysfs - CID and VMID masks.

coresight: etm4x: Improve usability of sysfs - CID and VMID masks.

Context ID and VM ID masks required 2 value inputs, even when the
second value is ignored as insufficient CID / VMID comparators are
implemented.

Permit a single value to be used if that is sufficient to cover all
implemented comparators.

Signed-off-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Link: https://lore.kernel.org/r/20191104181251.26732-10-mathieu.poirier@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>