vp8 quantization -> intrinsics

Use intrinsics for neon quantization. Slight loss (<5%) of performance
compared to the assembly. Roughly 10x faster on arm64 because that was
running C code before.

Change-Id: I7cf5242d8f29b7eab5bca6a1c20c89c9fc9ca66d
Remove pair quantization

The intrinsics version of the pair quant is slower than running it
individually.

Change-Id: I7b4ea8599d4aab04be0a5a0c59b8b29a7fc283f4
[spatial svc] Make spatial svc working for one pass rate control

Change-Id: Ibd9114485c3d747f9d148f64f706bf873ea473ac
Merge "[spatial svc] Make spatial svc working for one pass rate control"
Merge "vp8 quantization -> intrinsics"
Merge "Remove pair quantization"