kselftest: devices: Move discoverable devices test to subdirectory

Move the discoverable devices test to a subdirectory to allow other
related tests to be added to the devices directory.

Signed-off-by: Nícolas F. R. A. Prado <[e-mail]>
Acked-by: Shuah Khan <[e-mail]>
Acked-by: Greg Kroah-Hartman <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

tools/testing/selftests/Makefile

···
 TARGETS += cpufreq
 TARGETS += cpu-hotplug
 TARGETS += damon
-TARGETS += devices
+TARGETS += devices/probe
 TARGETS += dmabuf-heaps
 TARGETS += drivers/dma-buf
 TARGETS += drivers/s390x/uvdevice

tools/testing/selftests/devices/Makefile tools/testing/selftests/devices/probe/Makefile

···
 TEST_PROGS := test_discoverable_devices.py
 TEST_FILES := boards ksft.py
 
-include ../lib.mk
+include ../../lib.mk