build: Add rpm target
Add a top-level makefile target to build RPMs for Red Hat distributions
from the currently checked out commit. The resulting rpms are placed in
the packages/rpmbuild/RPMS/<arch> directory.
The rpm target is intended to be a convenience for testing changes to
the rpm packaging or generating packages for local testing.
Change-Id: Id951eb2b03629be59f6258e89e8356fe1fde1ff5
Reviewed-on: https://gerrit.openafs.org/14114
Reviewed-by: Andrew Deason <adeason@sinenomine.net>
Reviewed-by: Cheyenne Wills <cwills@sinenomine.net>
Reviewed-by: Benjamin Kaduk <kaduk@mit.edu>
Tested-by: BuildBot <buildbot@rampaginggeek.com>