libnvdimm, acpi, nfit: Add bus level dsm mask for pass thru.

Add a bus level dsm_mask to nvdimm_bus_descriptor to allow the passthru
calling mechanism to specify a different mask from the cmd_mask.

Populate bus_dsm_mask and use it to filter dsm calls that user can
make through the pass thru interface.

Signed-off-by: Jerry Hoemann <jerry.hoemann@hpe.com>
[djbw: use command number constants instead of a magic mask value]
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

include/linux/libnvdimm.h

@@ -55,6 +55,7 @@ typedef int (*ndctl_fn)(struct nvdimm_bus_descriptor *nd_desc,
 
 struct nvdimm_bus_descriptor {
 	const struct attribute_group **attr_groups;
+	unsigned long bus_dsm_mask;
 	unsigned long cmd_mask;
 	struct module *module;
 	char *provider_name;