libnvdimm, btt: BTT updates for UEFI 2.7 format

The UEFI 2.7 specification defines an updated BTT metadata format,
bumping the revision to 2.0. Add support for the new format, while
retaining compatibility for the old 1.1 format.

Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Linda Knippers <linda.knippers@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/include/linux/nd.h b/include/linux/nd.h
index 96069c5..5dc6b69 100644
--- a/include/linux/nd.h
+++ b/include/linux/nd.h
@@ -24,6 +24,7 @@ enum nvdimm_event {
 enum nvdimm_claim_class {
 	NVDIMM_CCLASS_NONE,
 	NVDIMM_CCLASS_BTT,
+	NVDIMM_CCLASS_BTT2,
 	NVDIMM_CCLASS_PFN,
 	NVDIMM_CCLASS_DAX,
 	NVDIMM_CCLASS_UNKNOWN,