drm/nouveau/devinit/tu102-: remove attempt at loading PreOS

From Turing, HW will already have handled this and locked-down the
falcon before we get control.  So this *should* be a no-op.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Acked-by: Danilo Krummrich <me@dakr.org>
Signed-off-by: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230919220442.202488-2-lyude@redhat.com