drm/panel: visionox-r66451: Set prepare_prev_first flag

The DSI host needs to be enabled for the panel to be initialized in
prepare(). Ensure this happens by setting prepare_prev_first.

Signed-off-by: Jessica Zhang <[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-visionox-r66451.c

···
 	dsi->lanes = 4;
 	dsi->format = MIPI_DSI_FMT_RGB888;
 	dsi->mode_flags = MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS;
+	ctx->panel.prepare_prev_first = true;
 
 	drm_panel_init(&ctx->panel, dev, &visionox_r66451_funcs, DRM_MODE_CONNECTOR_DSI);
 	ctx->panel.backlight = visionox_r66451_create_backlight(dsi);