drm/tests: Order Kunit tests in Makefile

Since we've recently added a ton of tests, the list starts to be a bit
of a mess and creates unneeded conflicts.

Let's order it alphabetically.
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v4-2-60d38873f782@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/tests/Makefile

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