drm/sysfs: fix hotplug regression since lifetime changes

airlied:
The lifetime changes introduced in 5bdebb18
tried to use device_create, however that led to the regression where dev->type
wasn't getting set correctly. First attempt at fixing it would have led to
a race, so this undoes the device_createa work and does it all manually
making sure the dev->type is setup before we register the device.

Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>