Fix DM9000 driver usage of spinlocks, which mainly came to light
when running a kernel with spinlock debugging. These come down to:

1) Un-initialised spin lock

2) Several cases of using  spin_xxx(lock) and not spin_xxx(&lock)

3) move the locking around the phy reg for read/write to only
   keep the lock when actually reading or writing to the phy.
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>