Revert "PM: devfreq: Add conservative governor"

This reverts commit 200b73d258e5d78b23ba762ccc7de7235c2aa29c.
PM: devfreq: Use high priority workqueue

It does not make sense to run kgsl on high and devfreq on regular
priority.
Govs: Update boost speed

Signed-off-by: dr87 <nb00870@gmail.com>
Add LS980 Support

Signed-off-by: dr87 <nb00870@gmail.com>