arm: u8500_hotplug: various changes

- make code more organised
- re-schedule early if not interactive governor or if hotplugging time delay is less than threshold
- fix some load get bugs
- tweak up load to online cpu1 more
- make hotplugging delay longer to allow a longer threshold
- some misc stuff i forgot that probably fixes some bugs and attains more performance

Change-Id: Ib49ba6310918783c3a759849c3f7639405ef5a96