drm: panel: boe-bf060y8m-aj0: Enable prepare_prev_first

Enable prepare_prev_first flag for BF060Y8M-AJ0 panel so that the
previous controller should be prepared first before the prepare for
the panel is called.

This makes sure that the previous controller, likely to be a DSI host
controller should be initialized to LP-11 before the panel is powered up.

Suggested-by: Marijn Suijten <[e-mail]>
Signed-off-by: Dang Huynh <[e-mail]>
Reviewed-by: Neil Armstrong <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/panel/panel-boe-bf060y8m-aj0.c

···
 	drm_panel_init(&boe->panel, dev, &boe_bf060y8m_aj0_panel_funcs,
 		       DRM_MODE_CONNECTOR_DSI);
 
+	boe->panel.prepare_prev_first = true;
+
 	boe->panel.backlight = boe_bf060y8m_aj0_create_backlight(dsi);
 	if (IS_ERR(boe->panel.backlight))
 		return dev_err_probe(dev, PTR_ERR(boe->panel.backlight),