drm/nouveau: Don't pm_runtime_put_sync(), only pm_runtime_put_autosuspend()

While trying to fix another issue, it occurred to me that I don't actually
think there is any situation where we want pm_runtime_put() in nouveau to
be synchronous. In fact, this kind of just seems like it would cause
issues where we may unexpectedly block a thread we don't expect to be
blocked.

So, let's only use pm_runtime_put_autosuspend().

Changes since v1:
* Use pm_runtime_put_autosuspend(), not pm_runtime_put()

Signed-off-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: David Airlie <airlied@linux.ie>
Fixes: 3a6536c5 ("drm/nouveau: Intercept ACPI_VIDEO_NOTIFY_PROBE")
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: <stable@vger.kernel.org> # v4.10+
Link: https://patchwork.freedesktop.org/patch/msgid/20220714174234.949259-3-lyude@redhat.com