Revert "drm/msm: dpu: Allow planes to extend past active display"

This reverts commit fb4dd7a9.

This is a preparation change for merging LTS tag v4.19.3 into
msm-kona branch.

DPU will not be used in 4.19 downstream display driver code.
Separate patches are submitted to introduce the downstream
version of the display driver.

Change-Id: I9359e01b9d92ffb14925d46e73af6ba98b4ffa7f
Signed-off-by: Blagovest Kolenichev <bkolenichev@codeaurora.org>