drm/sched: Use struct for drm_sched_init() params

drm_sched_init() has a great many parameters and upcoming new
functionality for the scheduler might add even more. Generally, the
great number of parameters reduces readability and has already caused
one missnaming, addressed in:

commit 6f1cacf4 ("drm/nouveau: Improve variable name in
nouveau_sched_init()").

Introduce a new struct for the scheduler init parameters and port all
users.

Reviewed-by: Liviu Dudau <liviu.dudau@arm.com>
Acked-by: Matthew Brost <matthew.brost@intel.com> # for Xe
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com> # for Panfrost and Panthor
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com> # for Etnaviv
Reviewed-by: Frank Binns <frank.binns@imgtec.com> # for Imagination
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com> # for Sched
Reviewed-by: Maíra Canal <mcanal@igalia.com> # for v3d
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Lizhi Hou <lizhi.hou@amd.com> # for amdxdna
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20250211111422.21235-2-phasta@kernel.org