MLK-22822:VPU Encoder: check the stream buffer free space before encode

MLK-22822:VPU Encoder: check the stream buffer free space before encode
frame

If the free space of stream buffer is not enough for one frame,
vpu may overwrite the data or hang.
so check before encode frame can avoid it.
Add new ctrl V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE,
user can use this ctrl to set the coded picture buffer size.

Signed-off-by: ming_qian <ming.qian@nxp.com>
Reviewed-by: Shijie Qin <shijie.qin@nxp.com>
(cherry picked from commit 1af0b35c6bfffa57e27f0a39c8b040b93d973278)