Drop DEPS_INCLUDE_DIR

Change-Id: I0f9cc195198ee17a7d98d244fc998bb4caf70c20
Reviewed-on: http://review.couchbase.org/35139
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>