kernel-*headers: Symlink videodev2 headers to linux/

The videodev2*.h headers were all stored exclusively in:
  kernel-*-headers/kernel-headers/

This is a huge problem as in some places, these headers are included as
"<videodev2.h>" and in other places "<linux/videodev2.h>". In the latter
case, the headers are completely missed and unused. At least somehow now
on Exynos 7885/7904 with a 4.4 kernel, where until now, that was causing
no apparent issues elsewhere.

On 7885, the proper headers going unused was causing incorrect V4L2
ioctls in libhwjpeg and libacryl. So, fix that by symlinking the
videodev2 headers to kernel-*-headers/kernel-headers/linux/, for 4.4
and also newer headers.

Change-Id: Id9aedba21e4a68d20fc83f6e49b367b686e19e18
10 files changed