Added rules to build 64-bit libraries: lib64cutils.a and lib64log.a

Both libraries are needed to build four shared libraries in 64-bit
for 64-bit emulator with "-gpu on"
  lib64OpenglRender.so
  lib64EGL_translator.so
  lib64GLES_CM_translator.so
  lib64GLES_V2_translator.so

Change-Id: If57f72d4661a74f1d5e537568881f39132e0b43d