IB/core, opa_vnic, hfi1, mlx5: Properly free rdma_netdev

IPOIB is calling free_rdma_netdev even though alloc_rdma_netdev has
returned -EOPNOTSUPP.
Move free_rdma_netdev from ib_device structure to rdma_netdev structure
thus ensuring proper cleanup function is called for the rdma net device.

Fix the following trace:

ib0: Failed to modify QP to ERROR state
BUG: unable to handle kernel paging request at 0000000000001d20
IP: hfi1_vnic_free_rn+0x26/0xb0 [hfi1]
Call Trace:
 ipoib_remove_one+0xbe/0x160 [ib_ipoib]
 ib_unregister_device+0xd0/0x170 [ib_core]
 rvt_unregister_device+0x29/0x90 [rdmavt]
 hfi1_unregister_ib_device+0x1a/0x100 [hfi1]
 remove_one+0x4b/0x220 [hfi1]
 pci_device_remove+0x39/0xc0
 device_release_driver_internal+0x141/0x200
 driver_detach+0x3f/0x80
 bus_remove_driver+0x55/0xd0
 driver_unregister+0x2c/0x50
 pci_unregister_driver+0x2a/0xa0
 hfi1_mod_cleanup+0x10/0xf65 [hfi1]
 SyS_delete_module+0x171/0x250
 do_syscall_64+0x67/0x150
 entry_SYSCALL64_slow_path+0x25/0x25

Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>