drm/msm/dpu: fix CMD panels on DPU 1.x - 3.x

drm/msm/dpu: fix CMD panels on DPU 1.x - 3.x

DPU units before 4.x don't have a separate CTL_START IRQ to mark the
begin of the data transfer. In such a case, wait for the frame transfer
to complete rather than trying to wait for the CTL_START interrupt (and
obviously hitting the timeout).

Fixes: 050770cbbd26 ("drm/msm/dpu: Fix timeout issues on command mode panels")
Reported-by: Alexey Minnekhanov <alexeymin@postmarketos.org>
Closes: https://lore.kernel.org/r/8e1d33ff-d902-4ae9-9162-e00d17a5e6d1@postmarketos.org
Patchwork: https://patchwork.freedesktop.org/patch/696490/
Link: https://lore.kernel.org/r/20251228-mdp5-drop-dpu3-v4-2-7497c3d39179@oss.qualcomm.com
Tested-by: Alexey Minnekhanov <alexeymin@minlexx.ru>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>