Except for dev_node_t, the contents of include/pcmcia/driver_ops.h
aren't used anywhere within the kernel. It's a left-over file from the
days when cardbus 32-bit cards weren't handled as pci devices, and
their drivers as pci drivers. So, move the dev_node_t to
include/pcmcia/ds.h, remove the lone in-kernel reference to
driver_ops.h, and remove the contents of driver_ops.h.