Fixed Build-Pkg to also include libn32 in $flistroot (mips64 specific see note)

Note: As mips64 can be build triarch multilib, 32bit pure, 64bit pure and
      mixed using 32bit data/64bit instructions (aka n32) and because we
      decided to symlink lib to the default userland libdir we have to
      include libn32, which is by the way not default for n32 libs and purely
      OpenSDE specific!

scripts/Build-Pkg

@@ -382,11 +382,12 @@ fi
 flistroot="bin boot etc lib sbin usr var opt"
 
 # additionally allowed toplevel directories for 64 bit architectures
+# TODO generate list from $arch_abis
 case $arch_machine in
         powerpc64|sparc64|x86_64|mips64)
                 var_append flistroot ' ' "lib64"
 		if [ "$SDECFG_MULTILIB" = 1 ]; then
-			var_append flistroot ' ' "lib32"
+			var_append flistroot ' ' "lib32 libn32"
 		fi
 		;;
 esac