video: Add function to obtain the U-Boot logo

It is useful to show the logo from other code, coming in a later feature.
Add a function to obtain it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/video/video-uclass.c b/drivers/video/video-uclass.c
index 9f22da0..fbe1ad1 100644
--- a/drivers/video/video-uclass.c
+++ b/drivers/video/video-uclass.c
@@ -406,6 +406,11 @@
 
 SPLASH_DECL(u_boot_logo);
 
+void *video_get_u_boot_logo(void)
+{
+	return SPLASH_START(u_boot_logo);
+}
+
 static int show_splash(struct udevice *dev)
 {
 	u8 *data = SPLASH_START(u_boot_logo);