winsup/doc: Remove ancient unused Makefile rules to make documentation tarball
This used to be used by cygwin-doc to make a tarball which would be used with a
ssh script to run docbook tools on a linux host since they weren't available on
Cygwin or something crazy like that...
2015-06-04 Jon Turney <jon.turney@dronecode.org.uk>
* Makefile.in: Remove ancient unused rules to make a documentation
tarball.
Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>