drm/panel: visionox-vtdr6130: Set prepare_prev_first flag

The DSI host must be enabled for the panel to be initialized in
prepare(). Set the prepare_prev_first flag to guarantee this.
Signed-off-by: Jessica Zhang <quic_jesszhan@quicinc.com>
Acked-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240201-visionox-vtdr-prev-first-v2-1-32db52867624@quicinc.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240201-visionox-vtdr-prev-first-v2-1-32db52867624@quicinc.com

drivers/gpu/drm/panel/panel-visionox-vtdr6130.c

@@ -287,6 +287,7 @@ static int visionox_vtdr6130_probe(struct mipi_dsi_device *dsi)
 	dsi->format = MIPI_DSI_FMT_RGB888;
 	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_NO_EOT_PACKET |
 			  MIPI_DSI_CLOCK_NON_CONTINUOUS;
+	ctx->panel.prepare_prev_first = true;
 
 	drm_panel_init(&ctx->panel, dev, &visionox_vtdr6130_panel_funcs,
 		       DRM_MODE_CONNECTOR_DSI);