drm/rockchip: Don't fully disable vop on self refresh

Instead of fully disabling and re-enabling the vop on self refresh
transitions, only disable the active windows. This will speed up
self refresh exits substantially and is still a power-savings win.

This patch integrates portions of Zain's patch from here:
https://patchwork.kernel.org/patch/9615063/

Changes in v2:
- None
Changes in v3:
- None
Changes in v4:
- Adjust for preceding vop_win_disable changes
Changes in v5:
- None

Link to v1: https://patchwork.freedesktop.org/patch/msgid/20190228210939.83386-5-sean@poorly.run
Link to v2: https://patchwork.freedesktop.org/patch/msgid/20190326204509.96515-4-sean@poorly.run
Link to v3: https://patchwork.freedesktop.org/patch/msgid/20190502194956.218441-10-sean@poorly.run
Link to v4: https://patchwork.freedesktop.org/patch/msgid/20190508160920.144739-11-sean@poorly.run

Cc: Zain Wang <wzz@rock-chips.com>
Cc: Tomasz Figa <tfiga@chromium.org>
Cc: Kristian H. Kristensen <hoegsberg@chromium.org>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611160844.257498-11-sean@poorly.run