Find Tivoli TSM headers in 64 bit location

Find Tivoli TSM headers in 64 bit location

When building with --enable-tivoli-tsm locate the Tivoli TSM headers
if they are installed in the path used by the 64 bit Tivoli TSM
installation.

Reviewed-on: https://gerrit.openafs.org/12258
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Michael Meffie <mmeffie@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
(cherry picked from commit 9c6e6d4c34d867639ac90ba9a46084f3700b57d1)

Change-Id: I7d47304eed94e0bc2607309985ac9247d6908e0c
Reviewed-on: https://gerrit.openafs.org/12259
Tested-by: BuildBot <buildbot@rampaginggeek.com>
Reviewed-by: Mark Vitale <mvitale@sinenomine.net>
Reviewed-by: Stephan Wiesand <stephan.wiesand@desy.de>