libnvdimm: Export nvdimm shutdown helper, nvdimm_delete()

CXL is a hotplug bus and arranges for nvdimm devices to be dynamically
discovered and removed. The libnvdimm core manages shutdown of nvdimm
security operations when the device is unregistered. That functionality
is moved to nvdimm_delete() and invoked by the CXL-to-nvdimm glue code.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/162379910271.2993820.2955889139842401250.stgit@dwillia2-desk3.amr.corp.intel.com


Signed-off-by: Dan Williams <dan.j.williams@intel.com>