drm/msm/dpu: fix WD timer handling on DPU 8.x

drm/msm/dpu: fix WD timer handling on DPU 8.x

Since DPU 8.x Watchdog timer settings were moved from the TOP to the
INTF block. Support programming the timer in the INTF block. Fixes tag
points to the commit which removed register access to those registers on
DPU 8.x+ (and which also should have added proper support for WD timer
on those devices).

Fixes: 43e3293fc614 ("drm/msm/dpu: add support for MDP_TOP blackhole")
Reviewed-by: Marijn Suijten <marijn.suijten@somainline.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/696586/
Link: https://lore.kernel.org/r/20251230-intf-fix-wd-v6-2-98203d150611@oss.qualcomm.com