$NetBSD: patch-doc_Makefile_in,v 1.2 2018/06/25 14:02:45 bouyer Exp $

Actually define all the targets used by the package's upper-level
makefiles.

--- ./doc/Makefile.in.orig	2017-10-29 11:08:50.000000000 +0100
+++ ./doc/Makefile.in	2018-06-25 14:51:22.354058038 +0200
@@ -16,6 +16,8 @@
 
 all: $(MANUAL).pdf $(MANUAL).html/index.html $(MANUAL).txt
 
+dep: ;
+
 install:
 	$(INSTALL) -d $(DESTDIR)$(docdir)
 	cp -rf $(srcdir)/*.txt $(DESTDIR)$(docdir)
