drm/amd/display: fix boot-up on vega10

Fixing null-deref on Vega10 due to regression after
'fix cursor related Pstate hang' change.
Added null checks in setting cursor position.
Signed-off-by: Roman Li <Roman.Li@amd.com>
Reviewed-by: Eric Yang <eric.yang2@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/dce110/dce110_hw_sequencer.c

@@ -2928,7 +2928,9 @@ void dce110_set_cursor_position(struct pipe_ctx *pipe_ctx)
 	if (pipe_ctx->top_pipe && pipe_ctx->plane_state != pipe_ctx->top_pipe->plane_state)
 		pos_cpy.enable = false;
 
+	if (ipp->funcs->ipp_cursor_set_position)
 		ipp->funcs->ipp_cursor_set_position(ipp, &pos_cpy, &param);
+	if (mi->funcs->set_cursor_position)
 		mi->funcs->set_cursor_position(mi, &pos_cpy, &param);
 }
 
@@ -2936,12 +2938,15 @@ void dce110_set_cursor_attribute(struct pipe_ctx *pipe_ctx)
 {
 	struct dc_cursor_attributes *attributes = &pipe_ctx->stream->cursor_attributes;
 
+	if (pipe_ctx->plane_res.ipp->funcs->ipp_cursor_set_attributes)
 		pipe_ctx->plane_res.ipp->funcs->ipp_cursor_set_attributes(
 				pipe_ctx->plane_res.ipp, attributes);
 
+	if (pipe_ctx->plane_res.mi->funcs->set_cursor_attributes)
 		pipe_ctx->plane_res.mi->funcs->set_cursor_attributes(
 				pipe_ctx->plane_res.mi, attributes);
 
+	if (pipe_ctx->plane_res.xfm->funcs->set_cursor_attributes)
 		pipe_ctx->plane_res.xfm->funcs->set_cursor_attributes(
 				pipe_ctx->plane_res.xfm, attributes);
 }