MAINTAINERS: add ndctl files to libnvdimm

The ndctl project under tools/ndctl/ provides a helper utility and
library interface to the libnvdimm sub-system.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/MAINTAINERS b/MAINTAINERS
index 527d137..bc9f081 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -7348,6 +7348,7 @@
 F:	include/linux/nd.h
 F:	include/linux/libnvdimm.h
 F:	include/uapi/linux/ndctl.h
+F:	tools/ndctl/*
 
 LIBNVDIMM BLK: MMIO-APERTURE DRIVER
 M:	Ross Zwisler <ross.zwisler@linux.intel.com>