MAINTAINERS: Add entry for device DAX

And update the entry for filesystem DAX to differentiate them.
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

MAINTAINERS

@@ -4162,7 +4162,7 @@ L:	linux-i2c@vger.kernel.org
 S:	Maintained
 F:	drivers/i2c/busses/i2c-diolan-u2c.c
 
-DIRECT ACCESS (DAX)
+FILESYSTEM DIRECT ACCESS (DAX)
 M:	Matthew Wilcox <mawilcox@microsoft.com>
 M:	Ross Zwisler <ross.zwisler@linux.intel.com>
 L:	linux-fsdevel@vger.kernel.org
@@ -4171,6 +4171,12 @@ F:	fs/dax.c
 F:	include/linux/dax.h
 F:	include/trace/events/fs_dax.h
 
+DEVICE DIRECT ACCESS (DAX)
+M:	Dan Williams <dan.j.williams@intel.com>
+L:	linux-nvdimm@lists.01.org
+S:	Supported
+F:	drivers/dax/
+
 DIRECTORY NOTIFICATION (DNOTIFY)
 M:	Jan Kara <jack@suse.cz>
 R:	Amir Goldstein <amir73il@gmail.com>