drm/msm/disp/dpu1: set vbif hw config to NULL to avoid use after memory free during pm runtime resume

BUG: Unable to handle kernel paging request at virtual address 006b6b6b6b6b6be3

Call trace:
dpu_vbif_init_memtypes+0x40/0xb8
dpu_runtime_resume+0xcc/0x1c0
pm_generic_runtime_resume+0x30/0x44
__genpd_runtime_resume+0x68/0x7c
genpd_runtime_resume+0x134/0x258
__rpm_callback+0x98/0x138
rpm_callback+0x30/0x88
rpm_resume+0x36c/0x49c
__pm_runtime_resume+0x80/0xb0
dpu_core_irq_uninstall+0x30/0xb0
dpu_irq_uninstall+0x18/0x24
msm_drm_uninit+0xd8/0x16c

Fixes: 25fdd5933e4c ("drm/msm: Add SDM845 DPU support")
Signed-off-by: Vinod Polimera <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/483255/
Link: https://lore.kernel.org/r/[e-mail]
[DB: fixed Fixes tag]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

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

···
 		for (i = 0; i < dpu_kms->catalog->vbif_count; i++) {
 			u32 vbif_idx = dpu_kms->catalog->vbif[i].id;
 
-			if ((vbif_idx < VBIF_MAX) && dpu_kms->hw_vbif[vbif_idx])
+			if ((vbif_idx < VBIF_MAX) && dpu_kms->hw_vbif[vbif_idx]) {
 				dpu_hw_vbif_destroy(dpu_kms->hw_vbif[vbif_idx]);
+				dpu_kms->hw_vbif[vbif_idx] = NULL;
+			}
 		}
 	}