drm/syncobj: call might_sleep before waiting for fence submission

If either the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT or
DRM_SYNCOBJ_WAIT_FLAGS_WAIT_AVAILABLE flags are passed to
drm_syncobj_array_wait_timeout, the function might sleep if the fence at
one of the given timeline points has not yet been submitted. Therefore,
we should call might_sleep in that case to catch potential bugs.

Signed-off-by: Erik Kurzinger <ekurzinger@nvidia.com>
Signed-off-by: Simon Ser <contact@emersion.fr>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Simon Ser <contact@emersion.fr>
Link: https://patchwork.freedesktop.org/patch/msgid/20240119163208.3723457-3-ekurzinger@nvidia.com