drivers: base: test: Add missing MODULE_* macros for platform devices tests

Commit b4cc44301b9d ("drivers: base: Add basic devm tests for platform
devices") introduced a new set of tests for platform devices that could
be compiled as a module, but didn't have the usual module macros.

Make sure they're there.

Fixes: b4cc44301b9d ("drivers: base: Add basic devm tests for platform devices")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230816073019.1446155-1-mripard@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: base: Free devm resources when unregistering a device

In the current code, devres_release_all() only gets called if the device
has a bus and has been probed.

This leads to issues when using bus-less or driver-less devices where
the device might never get freed if a managed resource holds a reference
to the device. This is happening in the DRM framework for example.

We should thus call devres_release_all() in the device_del() function to
make sure that the device-managed actions are properly executed when the
device is unregistered, even if it has neither a bus nor a driver.

This is effectively the same change than commit 2f8d16a996da ("devres:
release resources on device_del()") that got reverted by commit
a525a3ddeaca ("driver core: free devres in device_release") over
memory leaks concerns.

This patch effectively combines the two commits mentioned above to
release the resources both on device_del() and device_release() and get
the best of both worlds.

Fixes: a525a3ddeaca ("driver core: free devres in device_release")
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230720-kunit-devm-inconsistencies-test-v3-3-6aa7e074f373@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers: base: Add basic devm tests for platform devices

Platform devices show some inconsistencies with how devm resources are
released when the device has been probed and when it hasn't.

In particular, we can register device-managed actions no matter if the
device has be bound to a driver or not, but devres_release_all() will
only be called if it was bound to a driver or if there's no reference
held to it anymore.

If it wasn't bound to a driver and we still have a reference,
devres_release_all() will never get called. This is surprising
considering that if the driver isn't bound but doesn't have any
reference to it anymore, that function will get called, and if it was
bound to a driver but still has references, that function will get
called as well.

Even if that case is fairly unusual, it can easily lead to memory leaks.

The plan is, with the next patch, to make it consistent and enforce that
devres_release_all() is called no matter what situation we're in. For
now, it just tests for the current behaviour and skips over the
inconsistencies.

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20230720-kunit-devm-inconsistencies-test-v3-2-6aa7e074f373@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>