drm/tests: helpers: Add helper for drm_display_mode_from_cea_vic()

[ Upstream commit caa714f8 ]

As Maxime suggested, add a new helper
drm_kunit_display_mode_from_cea_vic(), it can replace the direct call
of drm_display_mode_from_cea_vic(), and it will help solving
the `mode` memory leaks.

Acked-by: Maxime Ripard <mripard@kernel.org>
Suggested-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241030023504.530425-2-ruanjinjie@huawei.com


Signed-off-by: Maxime Ripard <mripard@kernel.org>
Stable-dep-of: 70f29ca3 ("drm/tests: cmdline: Fix drm_display_mode memory leak")
Signed-off-by: Sasha Levin <sashal@kernel.org>