ffmpeg: update to 4.2.2-Matrix-Alpha1

[lrusak]

This is to go along with xbmc/xbmc#17300

Only updated the version and the patch that I maintain.

Will need the following updates:

• RPi patches
• MVC patches
• V4L2 Request patches
• V4L2 drmprime patches

[lrusak]

tested on linux-gbm with vaapi and all seems fine. http://ix.io/28LC

[Kwiboo]

please pick/squash/fixup Kwiboo@c4a9a8c for updated V4L2 Request patches

[MilhouseVH]

Generic test build with ffmpeg-4.2.2-Matrix-Alpha1: http://milhouse.libreelec.tv/builds/testing/Generic/LibreELEC-Generic.x86_64-9.80-Milhouse-20200131051644-%230131-gbe02e12.tar

Log: http://ix.io/28Me

2020-01-31 08:28:26.115 T:1161  NOTICE: Starting Kodi (19.0-ALPHA1 Git:177edb5). Platform: Linux x86 64-bit
2020-01-31 08:28:26.115 T:1161  NOTICE: Using Release Kodi x64 build
2020-01-31 08:28:26.115 T:1161  NOTICE: Kodi compiled 2020-01-31 by GCC 9.2.0 for Linux x86 64-bit version 5.4.16 (328720)
2020-01-31 08:28:26.115 T:1161  NOTICE: Running on LibreELEC (Milhouse.testing): devel-20200131051644-#0131-gbe02e12 [Build #0131] 9.80, kernel: Linux x86 64-bit version 5.4.16
2020-01-31 08:28:26.115 T:1161  NOTICE: FFmpeg version/source: 4.2.2-Kodi
2020-01-31 08:28:26.115 T:1161  NOTICE: Host CPU: Intel(R) Core(TM) i5-6260U CPU @ 1.80GHz, 4 cores available

[lrusak]

@Kwiboo thanks for the update.

[lrusak]

updated and squashed, should be good to go