When building this package on RPi4/armv7h, cmake will detect -march=armv7-a+simd (see src/kodi-build/CMakeFiles/CMakeOutput.log) which will conflict with the mcpu value we previously defined so just remove custom *FLAGS.
Also use ffmpeg 4.4.2 to match kodi-rpi and remove libva from depends which is not needed.
Use official ffmpeg 4.4.2 with Matrix
Doing so SEEMS TO avoid sporatic A/V sync issues with concomitant lines in the log like:
ActiveAE - large audio sync error: -89515.453679
ActiveAE - large audio sync error: -89515.536515
CVideoReferenceClock: detected 1 vblanks, missed 2, refreshrate might have changed
Also fixes broken HW accel decoding on more recent kernels, see: https://github.com/raspberrypi/linux/issues/5136
Removed the following parameters:
1. selinux=0
2. plymouth.enable=0
3. smsc95xx.turbo_mode=N
4. dwc_otg.lpm_enable=0
5. kgdboc=serial0,115200
Notes:
1. force not loading SELinux infrastructure which we currently do not supply
2. force disabling of plymouth which I think we do not supply
3. avoided network issues under heavy load circa 2012 likely no longer needed
4. turned off link power management which may have prevented issues with shitty
drivers in older kernels likely not an issue on a modern kernel tree
5. enabled debugging over the serial console which is unnecessary for most
user... advanced users will likely be savvy enough with cmdline.txt to
edit it to match their needs