IB/core: Export ioctl enum types to user-space

Add a new ib_user_ioctl_verbs.h which exports all required ABI
enums and structs to the user-space.
Export the default types to user-space through this file.

Signed-off-by: Matan Barak <matanb@mellanox.com>
Reviewed-by: Yishai Hadas <yishaih@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>