Philippe Gerum authored Jan 29, 2021 and Jan Kiszka committed Mar 08, 2021

In order to have applications calling clock_gettime(CLOCK_MONOTONIC)
and Cobalt share the same monotonic source, we need Cobalt to get
timestamps from ktime_get_mono_fast_ns().

Although pipeline_read_cycle_counter() does seem to hint to a raw
source, with Dovetail, our idea of time is directly based on a refined
count of nanoseconds since the epoch, the hardware time counter is
transparent to us. This naming discrepancy comes from the legacy
I-pipe support where we do manipulate hardware ticks internally; this
issue should go when such support is discontinued eventually.

Signed-off-by: Philippe Gerum <rpm@xenomai.org>