This is a rather old patch which re-orders the teardown of PCMCIA
network devices.  Current device drivers remove the IO mappings,
interrupts, and free any PCMCIA windows before they unregister
themselves from the network layer.

This patch ensures that we first unregister from the network layer
before performing any teardown of resources or windows.

Note: the only card which has been tested in this patch is pcnet_cs.