libafscp: makefile install rule update

Change the makefile install rules to install the header
file from the libafscp directory, and not the top level
include directory to make the install rules consistent
with the rest of the tree.

Reviewed-on: http://gerrit.openafs.org/10514
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 52fe3f52de95b698c93ca5da3c1ed59447817610)

Change-Id: I1ed7e92b8e27f3df8fc76ccaa6bac4199e40c180
Reviewed-on: http://gerrit.openafs.org/11228
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>