We may want to use the device pointer in device_init_wakeup() with
functions that expect the device to already be added with device_add().
For example, if we were to link the device initializing wakeup to
something in sysfs such as a class for wakeups we'll run into an error.
It looks like this code was written with the assumption that the device
would be added before initializing wakeup due to the order of operations
in power_supply_unregister().

Let's change the order of operations so we don't run into problems here.

Fixes: 948dcf96 ("power_supply: Prevent suspend until power supply events are processed")
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Tri Vo <trong@android.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Ravi Chandra Sadineni <ravisadineni@chromium.org>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>