The PVQ QM interpolation code needs to be adapted to AV1 ranges.

av1_float_pvq_dist_scale_AM_5f_Jan31@2017-02-02T08:57:23.156Z
 -> av1_float_pvq_dist_scale_AM_5f_Jan31_crfix@2017-02-02T15:14:40.477Z

  PSNR |  PSNR Cb | PSNR Cr | PSNR HVS |   SSIM | MS SSIM | CIEDE 2000
1.8501 | -29.0766 | -6.6775 |   1.8421 | 1.8252 |  1.8228 |    -9.9734

Change-Id: Ib72c1f8eeccf806f8d719866ce80172b6908643e