The various tap loop filter operations are common functions across
codec. This commit moves them along with SIMD optimizations to
vpx_dsp folder.
Change-Id: Ia5fa0b2e5289cdb98467502a549c380b9c60e92c
Create a new component, vpx_dsp, for code that can be shared
between codecs. Move the SAD code into the component.
This reduces the size of vpxenc/dec by 36k on x86_64 builds.
Change-Id: I73f837ddaecac6b350bf757af0cfe19c4ab9327a