xlat: update V4L2_* constants

xlat: update V4L2_* constants

* xlat/v4l2_control_ids.in
(V4L2_CID_MPEG_VIDEO_H264_CONSTRAINED_INTRA_PREDICTION): New constant
introduced by Linux kernel commit v5.1-rc1~88^2~261.
(V4L2_CID_MPEG_VIDEO_H264_CHROMA_QP_INDEX_OFFSET): New constant
introduced by Linux kernel commit v5.1-rc1~88^2~260.
* xlat/v4l2_pix_fmts.in (V4L2_PIX_FMT_AYUV32, V4L2_PIX_FMT_XYUV32,
V4L2_PIX_FMT_VUYA32, V4L2_PIX_FMT_VUYX32): New constants
introduced by Linux kernel commit v5.1-rc1~88^2~90.
* NEWS: Mention this.