trappy/ftrace: add support for boot clock timestamp

Created by: derkling

FTrace can be configured to report events timestamp using different clock sources which can be selected via the trace_clock sysfs attribute as described in: https://www.kernel.org/doc/Documentation/trace/ftrace.txt

The global clock source reports time in [s] with a [us] resolution. Other sources instead, like for example the boot clock, uses [ns]. Thus, in these last cases we do not have decimals in the timestamp.

Let's update the special fields regexp to match both [s] and [ns] formatted times. This also update the base test to add a set of trace events which are expressed in [ns] resolution.

Signed-off-by: Patrick Bellasi patrick.bellasi@arm.com