Make cmake default to lib, not lib64

This fixes flatpak/flatpak-builder#93

meta-freedesktop/recipes-devtools/cmake/cmake.inc

@@ -16,6 +16,7 @@ SRC_URI = "https://cmake.org/files/v${CMAKE_MAJOR_VERSION}/cmake-${PV}.tar.gz \
            file://qt4-fail-silent.patch \
            file://avoid-gcc-warnings-with-Wstrict-prototypes.patch \
            file://0001-KWIML-tests-Remove-format-security-from-flags.patch \
+           file://cmake-nolib64.patch \
            "
 
 SRC_URI[md5sum] = "79bd7e65cd81ea3aa2619484ad6ff25a"

meta-freedesktop/recipes-devtools/cmake/cmake/cmake-nolib64.patch

@@ -0,0 +1,15 @@
+diff -up cmake-3.7.2/Modules/GNUInstallDirs.cmake.orig cmake-3.7.2/Modules/GNUInstallDirs.cmake
+--- cmake-3.7.2/Modules/GNUInstallDirs.cmake.orig	2017-01-13 15:05:41.000000000 +0100
++++ cmake-3.7.2/Modules/GNUInstallDirs.cmake	2018-01-09 10:11:33.308481602 +0100
+@@ -210,9 +210,9 @@ if(NOT DEFINED CMAKE_INSTALL_LIBDIR OR (
+           "Please enable at least one language before including GNUInstallDirs.")
+       else()
+         if("${CMAKE_SIZEOF_VOID_P}" EQUAL "8")
+-          set(_LIBDIR_DEFAULT "lib64")
++          set(_LIBDIR_DEFAULT "lib")
+           if(DEFINED _GNUInstallDirs_LAST_CMAKE_INSTALL_PREFIX)
+-            set(__LAST_LIBDIR_DEFAULT "lib64")
++            set(__LAST_LIBDIR_DEFAULT "lib")
+           endif()
+         endif()
+       endif()