Enable these tests which run in native_posix in native_sim,
Switch from native_posix to native_sim as default test platform
For drivers.rand32.random_psa_crypto, filter the posix
arch to save some CI time, as TFM is not supported in this
architecture all together.
Signed-off-by: Alberto Escolar Piedras <alberto.escolar.piedras@nordicsemi.no>