lib: posix: clock: Turn clock_gettime into system call

Fix thread fault, on user mode, when reading variable rt_clock_base.
For the moment, clock_settime is left without system call:
we don't want to expose clock_settime without figuring out access
control

Signed-off-by: Julien D'Ascenzio <julien.dascenzio@paratronic.fr>
2 files changed