net: Fix OF platform drivers coldplug/hotplug when compiled as modules

Some OF platform drivers are missing module device tables, so they won't
load automatically on boot. This patch fixes the issue by adding proper
MODULE_DEVICE_TABLE() macros to the drivers.

Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>