Merge pull request #9567 from kaspar030/unify_test_target

tests/lwip_sock_udp/Makefile

tests/msg_avail/Makefile

tests/msg_send_receive/Makefile

tests/msg_try_receive/Makefile

tests/mutex_order/Makefile

tests/mutex_unlock_and_sleep/Makefile

tests/netdev_test/Makefile

tests/netstats_l2/Makefile

tests/nhdp/Makefile

tests/od/Makefile

tests/periph_timer/Makefile

tests/pipe/Makefile

tests/pkg_cayenne-lpp/Makefile

tests/pkg_fatfs_vfs/Makefile

tests/pkg_jsmn/Makefile

tests/pkg_libcoap/Makefile

tests/pkg_micro-ecc-with-hwrng/Makefile

tests/pkg_micro-ecc/Makefile

tests/pkg_minmea/Makefile

tests/pkg_monocypher/Makefile