Arm64 only supports float FFT tests.
Set the neon flags only for arm, not arm64.
Update to support arm64:

o arm64 uses neonintrinsic.c, not neon.c and neon_s.s.
o Use neon flags only when compiling for arm, not arm64.
Support SIMD instructions with arm64.
Fix 64-bit cleanliness issue.
Several fixes:
o Fix crash in inverse FFT caused by scribbling over the fft setup
  structure.
o Add NEON-optimized scaling since PFFFT doesn't do the necessary
  scaling on the inverse FFT.
Use the fast scaling for the CFFT too.
fft_time_pffft.c needs Neon to get a fast IFFT scale routine.
o Fix scaling of IFFT, which was off by a factor of 2 for complex
  IFFT.
o Compute the SNR and print it out to verify that the FFT is working
  correctly.
Merge branch 'rtoy-more-ffts-update-ne10-2014-06-24' of /usr/local/google/home/rtoy/work/clankium-master-arm64/src/openmax-hacks into rtoy-more-ffts-update-ne10-2014-06-24