netlink: specs: nl80211: drop structs which are not uAPI

netlink: specs: nl80211: drop structs which are not uAPI

C codegen will soon use structs for binary types. A handful of structs
in WiFi carry information elements from the wire, defined by the standard.
The structs are not part of uAPI, so we can't use them in C directly.
We could add them to the uAPI or add some annotation to tell the codegen
to output a local version to the user header. The former seems arbitrary
since we don't expose structs for most of the standard. The latter seems
like a lot of work for a rare occurrence. Drop the struct info for now.

Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/004030652d592b379e730be2f0344bebc4a03475.camel@sipsolutions.net
Link: https://patch.msgid.link/20250506194101.696272-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>