IB/uverbs: Allow resize CQ operation to return driver-specific data

Add a ib_uverbs_resize_cq_resp.driver_data field so that low-level
drivers can return data from a resize CQ operation to userspace.  Have
ib_uverbs_resize_cq() only copy the cqe field, to avoid having to bump
the userspace ABI.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/include/rdma/ib_user_verbs.h b/include/rdma/ib_user_verbs.h
index 7b53720..db1b814 100644
--- a/include/rdma/ib_user_verbs.h
+++ b/include/rdma/ib_user_verbs.h
@@ -275,6 +275,8 @@
 
 struct ib_uverbs_resize_cq_resp {
 	__u32 cqe;
+	__u32 reserved;
+	__u64 driver_data[0];
 };
 
 struct ib_uverbs_poll_cq {