config: use the standard INSTALL_DATA makefile macro

Replace the custom INST makefile macro with the standard
INSTALL_DATA macro for installing and exporting files.

Reviewed-on: http://gerrit.openafs.org/10723
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Derrick Brashear <shadow@your-file-system.com>
(cherry picked from commit 31d6467aa058a2b49c22188dfb0ca70b766d127f)

Change-Id: I7b7cc1d74c84090c9042b624af1c4e4b5c61ac6d
Reviewed-on: http://gerrit.openafs.org/11230
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Chas Williams - CONTRACTOR <chas@cmf.nrl.navy.mil>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>