pm: device: correct state in `pm_device_driver_init`

Set the value of `pm->state` as we move through the various stages of
`pm_device_driver_init`. This ensures hat if any of the code inside the
actions callbacks runs `pm_device_state_get` they get the correct state,
instead of always getting `PM_DEVICE_STATE_ACTIVE` (0, the value at
reset).

Signed-off-by: Jordan Yates <jordan@embeint.com>