This commit does the following things to fix compilation on FreeBSD:
1. Add required typedefs to linux/types-compat.h.
2. Remove unnecessary include linux/ioctl.h and replace linux/types.h
with linux/types-compat.h. Both files do not exist on FreeBSD.
3. Check the header including makedev macro. FreeBSD does not have
sys/sysmacros.h, and including it unconditionally causes error.
Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1259>
This introduces a GstV4L2CodecDevice structure and helper to retrieve a
list of CODEC device drivers. In order to find the device driver we
enumerate all media devices with UDEV. We then get the media controller
topology and locate a entity with function encoder or decoder and make
sure it is linked to two V4L2 IO entity pointing to the same device
node.
