drm/imx: add internal bridge handling display-timings DT node

i.MX DRM DT bindings allow using either a proper panel / bridge graph to
provide information about connected panels, or just a display-timings DT
node, describing just the timings and the flags. Add helper bridge
driver supporting the latter usecase. It will be used by both LDB and
parallel-display drivers.

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Tested-by: Chris Healy <cphealy@gmail.com>
Tested-by: Philipp Zabel <p.zabel@pengutronix.de> # on imx6q-nitrogen6x
Link: https://patchwork.freedesktop.org/patch/msgid/20240602-drm-imx-cleanup-v3-9-e549e2a43100@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>

include/drm/bridge/imx.h

@@ -0,0 +1,13 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2012 Sascha Hauer, Pengutronix
+ */
+
+#ifndef DRM_IMX_BRIDGE_H
+#define DRM_IMX_BRIDGE_H
+
+struct drm_bridge *devm_imx_drm_legacy_bridge(struct device *dev,
+					      struct device_node *np,
+					      int type);
+
+#endif