tools: ynl-gen: support full range of min/max checks for integer values

Extend the support to full range of min/max checks.
None of the existing YNL families required complex integer validation.

The support is less than trivial, because we try to keep struct nla_policy
tiny the min/max members it holds in place are s16. Meaning we can only
express checks in range of s16. For larger ranges we need to define
a structure and link it in the policy.

Link: https://lore.kernel.org/r/20231018163917.2514503-3-kuba@kernel.org


Signed-off-by: Jakub Kicinski <kuba@kernel.org>