drm/msm/sde: move current performance setting to crtc object

Current performance setting is maintained in crtc state, and its
update is synchronized to commit cycle. However, the setting may be
committed to clock and bandwidth driver out of sync with respect to
commit cycle, e.g. update at end of frame while another commit is
validating. As a result, requested settings may be missed and result
in older settings being used. Move current performance setting
to crtc object, from crtc state, so it can be updated at the
same time as the setting is committed to clock and bandwidth
driver.

CRs-Fixed: 2048612
Change-Id: I0c3047e8e806460105eaba5d46145798bd98d721
Signed-off-by: Alan Kwong <akwong@codeaurora.org>