ipq806x: add patch to support krait cpu scaling driver

This patch has been proposed but never actually merged to
mainline. It was accepted but never re proposed by the
creator.
Rework it, fix kernel panic cause by double kfree.

Tested-by: Stefan Lippers-Hollmann <s.l-h@gmx.de> [nbg6817/ipq8065]
Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>