IB/uverbs: Use __aligned_u64 for uapi headers

This has no impact on the structure layout since these structs already
have their u64s already properly aligned, but it does document that we
have this requirement for 32 bit compatibility.
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/uapi/rdma/rdma_user_ioctl.h

@@ -65,7 +65,7 @@ struct ib_uverbs_attr {
 	__u16 len;		/* only for pointers */
 	__u16 flags;		/* combination of UVERBS_ATTR_F_XXXX */
 	__u16 reserved;
-	__u64 data;		/* ptr to command, inline data or idr/fd */
+	__aligned_u64 data;	/* ptr to command, inline data or idr/fd */
 };
 
 struct ib_uverbs_ioctl_hdr {
@@ -73,7 +73,7 @@ struct ib_uverbs_ioctl_hdr {
 	__u16 object_id;
 	__u16 method_id;
 	__u16 num_attrs;
-	__u64 reserved;
+	__aligned_u64 reserved;
 	struct ib_uverbs_attr  attrs[0];
 };