ppl: fixed to use the right prefix to find libgmp and libgmpxx using pkgprefix

develop/ppl/ppl.conf

@@ -2,7 +2,7 @@
 # This copyright note is auto-generated by ./scripts/Create-CopyPatch.
 #
 # Filename: package/.../ppl/ppl.conf
-# Copyright (C) 2009 - 2010 The OpenSDE Project
+# Copyright (C) 2009 - 2012 The OpenSDE Project
 #
 # More information can be found in the files COPYING and README.
 #
@@ -17,6 +17,6 @@ if atstage toolchain; then
 	export CXX=g++
 	export LDFLAGS="-Wl,-rpath,${root}${libdir}"
 	var_append SYSGCC_WRAPPER_INSERT " " "-I${root}${includedir}"
-	var_append extraconfopt ' ' '--with-libgmp-prefix=$root'
-	var_append extraconfopt ' ' '--with-libgmpxx-prefix=$root'
+	var_append extraconfopt ' ' "--with-libgmp-prefix=$( pkgprefix -r gmp )"
+	var_append extraconfopt ' ' "--with-libgmpxx-prefix=$( pkgprefix -r gmp )"
 fi