drm/msm/dpu: Clear CTL_FETCH_PIPE_ACTIVE before blend setup

Before blend setup, all existing blend stages are cleared, so shall be
active fetch pipes.

Fixes: b3652e8 ("drm/msm/disp/dpu1: add support to program fetch active in ctl path")
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/651263/
Link: https://lore.kernel.org/r/20250430-b4-sm8750-display-v5-10-8cab30c3e4df@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>

Author: krzk

drivers/gpu/drm/msm/disp/dpu1/dpu_crtc.c

@@ -519,6 +519,8 @@ static void _dpu_crtc_blend_setup(struct drm_crtc *crtc)
 		if (mixer[i].lm_ctl->ops.clear_all_blendstages)
 			mixer[i].lm_ctl->ops.clear_all_blendstages(
 					mixer[i].lm_ctl);
+		if (mixer[i].lm_ctl->ops.set_active_fetch_pipes)
+			mixer[i].lm_ctl->ops.set_active_fetch_pipes(mixer[i].lm_ctl, NULL);
 	}
 
 	/* initialize stage cfg */