drm/xe: Move the coredump registration to the worker thread

Adding lockdep checking to the coredump code showed that there was an
existing violation. The dev_coredumpm_timeout() call is used to
register the dump with the base coredump subsystem. However, that
makes multiple memory allocations, only some of which use the GFP_
flags passed in. So that also needs to be deferred to the worker
function where it is safe to allocate with arbitrary flags.

In order to not add protoypes for the callback functions, moving the
_timeout call also means moving the worker thread function to later in
the file.

v2: Rebased after other changes to the worker function.

Fixes: e7994850 ("drm/xe: Introduce the dev_coredump infrastructure.")
Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Cc: Matthew Brost <matthew.brost@intel.com>
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Francois Dugast <francois.dugast@intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Lucas De Marchi <lucas.demarchi@intel.com>
Cc: "Thomas Hellström" <thomas.hellstrom@linux.intel.com>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: intel-xe@lists.freedesktop.org
Cc: linux-media@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Cc: linaro-mm-sig@lists.linaro.org
Cc: <stable@vger.kernel.org> # v6.8+
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241128210824.3302147-3-John.C.Harrison@Intel.com


(cherry picked from commit 90f51a7f)
Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>