libnvdimm: Add DSM support for Address Range Scrub commands

Add support for the three ARS DSM commands:
- Query ARS Capabilities - Queries the firmware to check if a given
  range supports scrub, and if so, which type (persistent vs. volatile)
- Start ARS - Starts a scrub for a given range/type
- Query ARS Status - Checks status of a previously started scrub, and
  provides the error logs if any.

  The commands are described by the example DSM spec at:
  http://pmem.io/documents/NVDIMM_DSM_Interface_Example.pdf

Also add these commands to the nfit_test test framework, and return
canned data.

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/acpi/nfit.h

@@ -107,6 +107,7 @@ struct acpi_nfit_desc {
 	struct nvdimm_bus *nvdimm_bus;
 	struct device *dev;
 	unsigned long dimm_dsm_force_en;
+	unsigned long bus_dsm_force_en;
 	int (*blk_do_io)(struct nd_blk_region *ndbr, resource_size_t dpa,
 			void *iobuf, u64 len, int rw);
 };