Remove mk/find-prefix.mk usage from the cad category.

The find-prefix infrastructure was required in a pkgviews world where
packages installed from pkgsrc could have different installation
prefixes, and this was a way for a dependency prefix to be determined.

Now that pkgviews has been removed there is no longer any need for the
overhead of this infrastructure.  Instead we use BUILDLINK_PREFIX.pkg
for dependencies pulled in via buildlink, or LOCALBASE/PREFIX where the
dependency is coming from pkgsrc.

Provides a reasonable performance win due to the reduction of `pkg_info
-qp` calls, some of which were redundant anyway as they were duplicating
the same information provided by BUILDLINK_PREFIX.pkg.

cad/geda/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.103 2015/11/18 14:19:48 ryoon Exp $
+# $NetBSD: Makefile,v 1.104 2015/11/25 12:48:18 jperkin Exp $
 
 DISTNAME=	geda-gaf-1.8.2
 PKGNAME=	${DISTNAME:S/-gaf-/-/}
@@ -50,8 +50,7 @@ REPLACE_PERL+=		utils/scripts/pads_backannotate \
 # needs GNU m4 for the PCBboard and gsch2pcb netlisters
 USE_TOOLS+=		gmake m4:run pkg-config
 
-EVAL_PREFIX+=	PCBDIR=pcb
-CONFIGURE_ARGS+=	--with-pcbm4dir=${PCBDIR}/share/pcb/m4
+CONFIGURE_ARGS+=	--with-pcbm4dir=${LOCALBASE}/share/pcb/m4
 CONFIGURE_ARGS+=	--with-pcbconfdir=${PKG_SYSCONFDIR}/pcb
 
 SUBST_CLASSES+=			python
@@ -64,8 +63,7 @@ REPLACE_SH+=		gnetlist/scripts/sch2eaglepos.sh
 USE_TOOLS+=		sh:run
 
 # for gsch2pcb
-EVAL_PREFIX+=		PCBDIR=pcb
-CONFIGURE_ARGS+=	--with-pcb-datadir=${PCBDIR}/share
+CONFIGURE_ARGS+=	--with-pcb-datadir=${LOCALBASE}/share
 USE_TOOLS+=		gawk:run lex perl:run pkg-config
 
 # disable groff for a consistent build

cad/gwave/Makefile

@@ -1,4 +1,4 @@
-# $NetBSD: Makefile,v 1.63 2015/06/12 10:48:26 wiz Exp $
+# $NetBSD: Makefile,v 1.64 2015/11/25 12:48:18 jperkin Exp $
 #
 
 DISTNAME=	gwave2-20090213
@@ -18,8 +18,7 @@ GNU_CONFIGURE=	YES
 USE_LIBTOOL=	yes
 USE_TOOLS+=	perl pkg-config
 
-EVAL_PREFIX+=	GRAPHDIR=plotutils
-CONFIGURE_ENV+=	GRAPH=${GRAPHDIR}/bin/graph
+CONFIGURE_ENV+=	GRAPH=${BUILDLINK_PREFIX.plotutils}/bin/graph
 
 LDFLAGS.DragonFly=	-lX11
 LDFLAGS.SunOS+=		-lX11