src: use definitions in include/linux/netfilter/nf_tables.h

src: use definitions in include/linux/netfilter/nf_tables.h

Use NFT_LOGLEVEL_* definitions in UAPI.

Make an internal definition of NFT_OSF_F_VERSION, this was originally
defined in the UAPI header in the initial patch version, however, this
is not available anymore.

Add a bison rule to deal with the timeout case.

Otherwise, compilation breaks.

Fixes: d3869cae9d62 ("include: refresh nf_tables.h cached copy")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>