Various RDMA headers are intended to be exported to userspace, so add
them to the headers-y list.  Add a (strictly speaking, superfluous)
include of <linux/types.h> to avoid a headers_check warning.
Signed-off-by: NRoland Dreier <roland@purestorage.com>

Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>

This adds the Kbuild files listing the files which are to be installed by
the 'headers_install' make target, in generic directories.
Signed-off-by: NDavid Woodhouse <dwmw2@infradead.org>