Make hcrypto depend on config

Make hcrypto depend on config

hcrypto needs the top-level include structure to be present so it
can install its header files.  Add a dependency to "config" in
the Makefile to make this explicit and prevent occasional failures
with parallel builds.

Change-Id: If588d6a15fa1fdf371ec2841cc3a6e75077cccb0
Reviewed-on: http://gerrit.openafs.org/2620
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Reviewed-by: Simon Wilkinson <sxw@inf.ed.ac.uk>
Reviewed-by: Derrick Brashear <shadow@dementia.org>
Tested-by: Derrick Brashear <shadow@dementia.org>