Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This merges the work of Danilo Sabato, who made the ppsi daemon build
both on i386 and x86-64 in a lib-less fashion.  Such architectures
are meant to show ppsi running on bare metal, and are test benches
for any changes to the core, even for people who cannot build and run
on real bare-metal hosts.

According to configuration, pp_diag_verbosity can be "const" or not
(having it const saves a lot of space and we need it in our
white-rabbit core).

This avoids errors when building for all architectures, with or
without CONFIG_PPSI_RUNTIME_VERBOSITY.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

arch-bare-x86-64: bugfix for packet receive
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Not all libraries offer CLOCK_MONOTONIC_RAW, and actually it gives
no advantage over CLOCK_MONOTONIC in our context.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Acked-by: Aurelio Colosimo <aurelio@aureliocolosimo.it>

Signed-off-by: Aurelio Colosimo <aurelio@aureliocolosimo.it>