ibm_newemac: Call dev_set_drvdata() before tah_reset()

The patch moves dev_set_drvdata(&ofdev->dev, dev) up before tah_reset(ofdev)
is called to avoid a NULL pointer dereference, since tah_reset uses drvdata.

Signed-off-by: Valentine Barshak <vbarshak@ru.mvista.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>