* Select always PICOLIBC. This is anyhow the default for all
but the posix architecture. And for the posix architecture
we need it as POSIX_CLOCK does not work with the host C
library.
* Fix the testcase filtering. This sample works fine
in native_sim (when not using the host libC),
but does not work for native_posix(_64), as those can
only be built with the host libC, and in that case,
the POSIX_CLOCK provided functions will not be properly
linked to.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>