drm: selftest: convert drm_plane_helper selftest to KUnit

Considering the current adoption of the KUnit framework, convert the
DRM plane helper selftest to the KUnit API.
Co-developed-by: Djakson C. G. Filho <djakson.filho@gmail.com>
Signed-off-by: Djakson C. G. Filho <djakson.filho@gmail.com>
Co-developed-by: Anderson Fraga <aaafraga@gmail.com>
Signed-off-by: Anderson Fraga <aaafraga@gmail.com>
Tested-by: David Gow <davidgow@google.com>
Acked-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Maíra Canal <maira.canal@usp.br>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220708203052.236290-6-maira.canal@usp.br

drivers/gpu/drm/selftests/Makefile

 # SPDX-License-Identifier: GPL-2.0-only
-test-drm_modeset-y := test-drm_modeset_common.o test-drm_plane_helper.o \
-                      test-drm_framebuffer.o test-drm_dp_mst_helper.o
+test-drm_modeset-y := test-drm_modeset_common.o test-drm_framebuffer.o \
+					test-drm_dp_mst_helper.o
 
 obj-$(CONFIG_DRM_DEBUG_SELFTEST) += test-drm_mm.o test-drm_modeset.o \
 				    test-drm_buddy.o

drivers/gpu/drm/selftests/drm_modeset_selftests.h

@@ -6,7 +6,6 @@
  *
  * Tests are executed in order by igt/drm_selftests_helper
  */
-selftest(check_plane_state, igt_check_plane_state)
 selftest(check_drm_framebuffer_create, igt_check_drm_framebuffer_create)
 selftest(dp_mst_calc_pbn_mode, igt_dp_mst_calc_pbn_mode)
 selftest(dp_mst_sideband_msg_req_decode, igt_dp_mst_sideband_msg_req_decode)

drivers/gpu/drm/selftests/test-drm_modeset_common.h

@@ -16,7 +16,6 @@
 
 #define FAIL_ON(x) FAIL((x), "%s", "FAIL_ON(" __stringify(x) ")\n")
 
-int igt_check_plane_state(void *ignored);
 int igt_check_drm_framebuffer_create(void *ignored);
 int igt_dp_mst_calc_pbn_mode(void *ignored);
 int igt_dp_mst_sideband_msg_req_decode(void *ignored);

drivers/gpu/drm/tests/Makefile

 # SPDX-License-Identifier: GPL-2.0
 
 obj-$(CONFIG_DRM_KUNIT_TEST) += drm_format_helper_test.o drm_damage_helper_test.o \
-	drm_cmdline_parser_test.o drm_rect_test.o drm_format_test.o
+	drm_cmdline_parser_test.o drm_rect_test.o drm_format_test.o drm_plane_helper_test.o