drm/mxsfb: Read bus flags from bridge if present

The bridge might have special requirmentes on the input bus. This
is e.g. used by the imx-nwl bridge.

Signed-off-by: Guido Günther <[e-mail]>
Reviewed-by: Stefan Agner <[e-mail]>
Signed-off-by: Stefan Agner <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/mxsfb/mxsfb_crtc.c

···
 {
 	struct drm_device *drm = mxsfb->pipe.crtc.dev;
 	struct drm_display_mode *m = &mxsfb->pipe.crtc.state->adjusted_mode;
-	const u32 bus_flags = mxsfb->connector->display_info.bus_flags;
+	u32 bus_flags = mxsfb->connector->display_info.bus_flags;
 	u32 vdctrl0, vsync_pulse_len, hsync_pulse_len;
 	int err;
 
···
 		return;
 
 	clk_set_rate(mxsfb->clk, m->crtc_clock * 1000);
+
+	if (mxsfb->bridge && mxsfb->bridge->timings)
+		bus_flags = mxsfb->bridge->timings->input_bus_flags;
 
 	DRM_DEV_DEBUG_DRIVER(drm->dev, "Pixel clock: %dkHz (actual: %dkHz)\n",
 			     m->crtc_clock,