avcodec/cavs: make cavs_chroma_qp non static

The table is needed by multiple files

Reverts part of ef07ac1e126b95ad7e1b56504c19b59901265c3e

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
avcodec/cavs: improve conformance with rm52j reference decoder

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>