drm/amd/powerplay: add pptable point check before use it

Signed-off-by: Rex Zhu <Rex.Zhu@amd.com>
Acked-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Edward O'Callaghan <funfunctor@folklore1984.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
diff --git a/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c b/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
index 82427fb..1b3151c 100644
--- a/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
+++ b/drivers/gpu/drm/amd/powerplay/hwmgr/hwmgr.c
@@ -555,7 +555,8 @@
 		table_clk_vlt->entries[2].v = 810;
 		table_clk_vlt->entries[3].clk = PP_DAL_POWERLEVEL_PERFORMANCE;
 		table_clk_vlt->entries[3].v = 900;
-		pptable_info->vddc_dep_on_dal_pwrl = table_clk_vlt;
+		if (pptable_info != NULL)
+			pptable_info->vddc_dep_on_dal_pwrl = table_clk_vlt;
 		hwmgr->dyn_state.vddc_dep_on_dal_pwrl = table_clk_vlt;
 	}