pkgconfig: prefix pkg-config with arch triplet at toolchain stage

base/pkgconfig/pkgconfig.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../pkgconfig/pkgconfig.conf
-# Copyright (C) 2006 - 2008 The OpenSDE Project
+# Copyright (C) 2006 - 2014 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -27,4 +27,6 @@ fi
 
 if ! atstage toolchain; then
 	hook_add postmake 5 'cp -vf $confdir/etc_profile.d_pkgconfig.txt $root/etc/profile.d/pkgconfig'
+else
+	var_append extraconfopt ' ' '--program-prefix=${arch_target}-'
 fi