Fix a few libc makefile mishaps.

These are the problems fixed in this CL:

- The ndk_cruft.cpp file was not compiled for 64 bit.
- Some files where not compiled for libc_bionic.a due to a missing
  patch-up-arch-specific-flags call.
- The libc_bionic_ndk.a patch up call was using bionic src, not
  the bionic_ndk_src_files.
- Move mmap.cpp to the ndk src list where it was before because of
  the above errors.

Bug: 21640784
Change-Id: I31e97bc8bf347c8e584cc17aa4b984a7d122b298