ideapad_laptop: remove ideapad_handle and ideapad_priv

The current code use ideapad_handle and ideapad_priv to store
some information for the ideapad device.
But as they are global/static variables, the driver will be broken
if there are more than one ideapad ACPI device node on a platform.
Although this does not happen for now and may not happen in the future,
but still, this is a software bug.

Remove these two variables in this patch.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
CC: Matthew Garrett <matthew.garrett@nebula.com>
CC: Ike Panhc <ike.pan@canonical.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>