PM: runtime: Drop DEFINE_FREE() for pm_runtime_put()

The DEFINE_FREE() for pm_runtime_put has been superseded by recently
introduced runtime PM auto-cleanup macros and its only user has been
converted to using one of the new macros, so drop it.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>