Add neon optimized dequantization and inverse DCT.

Implements unscaled and scaled dequantization
and inverse DCT functions in Neon assembler.
Optimizes web and gallery application use case.

Change-Id: Iee4ebfbad7c0dd049e7d9c3fc4b48aca0df208d3
Signed-off-by: Patrik Ryd <patrik.ryd@stericsson.com>
Signed-off-by: Henrik Smiding <henrik.smiding@stericsson.com>
Add neon optimized color conversion.

Implements all upsampling color conversion functions in
Neon assembler. Optimizes web and gallery application use case.

Signed-off-by: Christian Bejram <christian.bejram@stericsson.com>
Change-Id: I8d89ba7bb8447ea071d72aff0a156652997dec82