IB/{core,hw}: Add constant for node_desc

drivers/infiniband/core/sysfs.c

drivers/infiniband/hw/cxgb3/iwch_provider.c

drivers/infiniband/hw/cxgb4/provider.c

drivers/infiniband/hw/hfi1/verbs.c

drivers/infiniband/hw/mlx4/mad.c

drivers/infiniband/hw/mlx4/main.c

drivers/infiniband/hw/mlx5/mad.c

drivers/infiniband/hw/mlx5/main.c

drivers/infiniband/hw/mthca/mthca_mad.c

drivers/infiniband/hw/mthca/mthca_provider.c

drivers/infiniband/hw/ocrdma/ocrdma_main.c

drivers/infiniband/hw/qib/qib_verbs.c

include/rdma/ib_verbs.h