drm/tests: Introduce a config option for the KUnit helpers

Driver-specific tests will need access to the helpers without pulling
every DRM framework test. Let's create an intermediate Kconfig options
for the helpers.
Suggested-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20221123-rpi-kunit-tests-v3-2-4615a663a84a@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/Kconfig

@@ -63,6 +63,12 @@ config DRM_USE_DYNAMIC_DEBUG
 	  bytes per callsite, the .data costs can be substantial, and
 	  are therefore configurable.
 
+config DRM_KUNIT_TEST_HELPERS
+	tristate
+	depends on DRM && KUNIT
+	help
+	  KUnit Helpers for KMS drivers.
+
 config DRM_KUNIT_TEST
 	tristate "KUnit tests for DRM" if !KUNIT_ALL_TESTS
 	depends on DRM && KUNIT
@@ -73,6 +79,7 @@ config DRM_KUNIT_TEST
 	select DRM_KMS_HELPER
 	select DRM_BUDDY
 	select DRM_EXPORT_FOR_TESTS if m
+	select DRM_KUNIT_TEST_HELPERS
 	default KUNIT_ALL_TESTS
 	help
 	  This builds unit tests for DRM. This option is not useful for

drivers/gpu/drm/Makefile

@@ -125,7 +125,7 @@ obj-$(CONFIG_DRM_KMS_HELPER) += drm_kms_helper.o
 # Drivers and the rest
 #
 
-obj-$(CONFIG_DRM_KUNIT_TEST) += tests/
+obj-y			+= tests/
 
 obj-$(CONFIG_DRM_MIPI_DBI) += drm_mipi_dbi.o
 obj-$(CONFIG_DRM_MIPI_DSI) += drm_mipi_dsi.o

drivers/gpu/drm/tests/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
+obj-$(CONFIG_DRM_KUNIT_TEST_HELPERS) += \
+	drm_kunit_helpers.o
+
 obj-$(CONFIG_DRM_KUNIT_TEST) += \
 	drm_buddy_test.o \
 	drm_cmdline_parser_test.o \
@@ -9,7 +12,6 @@ obj-$(CONFIG_DRM_KUNIT_TEST) += \
 	drm_format_helper_test.o \
 	drm_format_test.o \
 	drm_framebuffer_test.o \
-	drm_kunit_helpers.o \
 	drm_mm_test.o \
 	drm_modes_test.o \
 	drm_plane_helper_test.o \