kselftest: Add test to verify probe of devices from discoverable buses

Add a new test to verify that a list of expected devices from
discoverable buses (ie USB, PCI) have been successfully instantiated and
probed by a driver.

The per-platform list of expected devices is selected from the ones
under the boards/ directory based on the DT compatible or the DMI IDs.

Signed-off-by: "Nícolas F. R. A. Prado" <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20240122-discoverable-devs-ksft-v4-1-d602e1df4aa2@collabora.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>