Avoid building PS and PDF docs, which do not build bit-reproducible.  NASM
already installs doc in info and html.

--- nasm-2.12.01/doc/Makefile.in.orig	2016-06-21 18:02:59.483484829 +0200
+++ nasm-2.12.01/doc/Makefile.in	2016-06-21 18:03:46.700151410 +0200
@@ -27,7 +27,7 @@
 PS2PDF          = @PS2PDF@		# Part of GhostScript
 
 SRCS		= nasmdoc.src inslist.src changes.src
-OUT		= info html nasmdoc.txt nasmdoc.ps nasmdoc.pdf
+OUT		= info html nasmdoc.txt
 
 # exports
 export srcdir
@@ -100,4 +100,4 @@
 	$(INSTALL_DATA) info/* $(INSTALLROOT)$(infodir)
 	mkdir -p $(INSTALLROOT)$(docdir)/html
 	$(INSTALL_DATA) html/* $(INSTALLROOT)$(docdir)/html
-	$(INSTALL_DATA) nasmdoc.ps nasmdoc.pdf nasmdoc.txt $(INSTALLROOT)$(docdir)
+	$(INSTALL_DATA) nasmdoc.txt $(INSTALLROOT)$(docdir)
