drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS

drivers: base: test: Enable device model tests with KUNIT_ALL_TESTS

Per commit bebe94b53eb7 ("drivers: base: default KUNIT_* fragments to
KUNIT_ALL_TESTS"), it seems like we should default to KUNIT_ALL_TESTS.

This enables these platform_device tests for common configurations, such
as with:
  ./tools/testing/kunit/kunit.py run

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20241216201148.535115-3-briannorris@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>