libnvdimm/pmem: Delete include of nd-core.h

The entire point of nd-core.h is to hide functionality that no leaf
driver should touch. In fact, the commit that added it had no need to
include it.

Fixes: 06e8ccdab1 ("acpi: nfit: Add support for detect platform...")
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/nvdimm/pmem.c

@@ -28,7 +28,6 @@
 #include "pmem.h"
 #include "pfn.h"
 #include "nd.h"
-#include "nd-core.h"
 
 static struct device *to_dev(struct pmem_device *pmem)
 {