tools: ynl-gen: add makefile deps for neigh

tools: ynl-gen: add makefile deps for neigh

Kory is reporting build issues after recent additions to YNL
if the system headers are old.

Link: https://lore.kernel.org/20250519164949.597d6e92@kmaincent-XPS-13-7390
Reported-by: Kory Maincent <kory.maincent@bootlin.com>
Fixes: 0939a418b3b0 ("tools: ynl: submsg: reverse parse / error reporting")
Tested-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20250520161916.413298-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>