ffmpeg: upgrade 5.1.1 -> 5.1.2

version 5.1.2:
- avcodec/dstdec: Check for overflow in build_filter()
- avformat/spdifdec: Use 64bit to compute bit rate
- avformat/rpl: Use 64bit for duration computation
- avformat/xwma: Use av_rescale() for duration computation
- avformat/sdsdec: Use av_rescale() to avoid intermediate overflow in duration calculation
- avformat/sbgdec: Check ts_int in genrate_intervals
- avformat/sbgdec: clamp end_ts
- avformat/rmdec: check tag_size
- avformat/nutdec: Check fields
- avformat/flvdec: Use 64bit for sum_flv_tag_size
- avformat/jacosubdec: Fix overflow in get_shift()
- avformat/genh: Check nb_channels for IMA ADPCM
- avformat/dxa: avoid bpc overflows
- avformat/dhav: Use 64bit seek_back
- avformat/cafdec: Check that nb_frasmes fits within 64bit
- avformat/asfdec_o: Limit packet offset
- avformat/apm: Use 64bit for bit_rate computation
- avformat/ape: Check frames size
- avformat/icodec: Check nb_pal
- avformat/aiffdec: Use 64bit for block_duration use
- avformat/aiffdec: Check block_duration
- avformat/mxfdec: only probe max run in
- avformat/mxfdec: Check run_in is within 65536
- avcodec/mjpegdec: Check for unsupported bayer case
- avcodec/apedec: Fix integer overflow in filter_3800()
- avcodec/tta: Check 24bit scaling for overflow
- avcodec/mobiclip: Check quantizer for overflow
- avcodec/exr: Check preview psize
- avcodec/tiff: Fix loop detection
- libavformat/hls: Free keys
- avcodec/fmvc: Move frame allocation to a later stage
- avfilter/vf_showinfo: remove backspaces
- avcodec/speedhq: Check width
- avcodec/bink: disallow odd positioned scaled blocks
- avformat/cafenc: derive Opus frame size from the relevant stream parameters
- avformat/dashdec: Fix crash on invalid input/ENOMEM, fix leak
- lavc/videotoolbox: do not pass AVCodecContext to decoder output callback
- lavc/pthread_frame: always transfer stashed hwaccel state
- avcodec/arm/sbcenc: avoid callee preserved vfp registers
- avformat/riffdec: don't unconditionally overwrite WAVEFORMATEXTENSIBLE layout
- avfilter/vf_scale: overwrite the width and height expressions with the original values
- lavc/pthread_frame: avoid leaving stale hwaccel state in worker threads
- avutil/tests/.gitignore: Add channel_layout testtool

Signed-off-by: Alexander Kanavin <alex@linutronix.de>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
(cherry picked from commit 32da2113)
Signed-off-by: Steve Sakoman <steve@sakoman.com>