This adds a bit more build coverage for the tests even though these are
not expected to be enabled by normal users and distros. In order to make
this working we need to open-code kunit_test_suite() and call the
relevant functions directly in the driver init/exit hook.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

We can test some parts of tunneling, like path allocation without access
to test hardware so add KUnit tests for PCIe, DP and USB3 tunneling.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>

This adds KUnit tests for path walking which is only dependent on
software structures, so no hardware is needed to run these.

We make these available only when both KUnit and the driver itself are
built into the kernel image. The reason for this is that KUnit adds its
own module_init() call in kunit_test_suite() which generates linker
error because the driver does the same in nhi.c. This should be fine for
now because these tests are only meant to run by developers anyway.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>