netlink: specs: fixup openvswitch specs for code generation

Refine the ovs_* specs to align exactly with the ovs netlink UAPI
definitions to enable code generation.

Signed-off-by: Donald Hunter <donald.hunter@gmail.com>
Link: https://lore.kernel.org/r/20230615151405.77649-1-donald.hunter@gmail.com


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