This moves the existing adapter checking into the platform layer and
moves the Windows implementation to its platform implementation and adds
a Linux implementation based on directly querying VA-API.
Unlike Windows, this check takes ~1ms so we have no need to spin out
another thread to perform the work. This also fixes up some of the CPP/C
mixing going on in common_utils."h" to allow us to call common functions
from C files.
Intel committed an NDA disclaimer on each source file. The stated
intention was that the NDA "added to OBS doesn't apply to open source
code once it's been accepted by the community. You can remove it for
your modifications". This quote is from an email chain involving
Intel's legal team and developers. The NDA in the source files
mistakenly triggers source code scanners that look for license
violations. I have removed the comments that contain the NDA.
Code submissions have continually suffered from formatting
inconsistencies that constantly have to be addressed. Using
clang-format simplifies this by making code formatting more consistent,
and allows automation of the code formatting so that maintainers can
focus more on the code itself instead of code formatting.
