Migrate quantization functions from vp9/ to vpx_dsp/

The following quantization functions were moved:
vp9_quantize_b
vp9_quantize_b_32x32
vp9_highbd_quantize_b
vp9_highbd_quantize_b_32x32

vp9_quantize_dc
vp9_quantize_dc_32x32
vp9_highbd_quantize_dc
vp9_highbd_quantize_dc_32x32

The purpose of doing that was to allow these functions to be shared
by multiple codecs.

Change-Id: Id8ab939f283353cdd07bd930d47db3d932a5d87f
17 files changed