of: Preserve "of-display" device name for compatibility

Since commit 241d2fb5 ("of: Make OF framebuffer device names unique"),
as spotted by Frédéric Bonnard, the historical "of-display" device is
gone: the updated logic creates "of-display.0" instead, then as many
"of-display.N" as required.

This means that offb no longer finds the expected device, which prevents
the Debian Installer from setting up its interface, at least on ppc64el.

Fix this by keeping "of-display" for the first device and "of-display.N"
for subsequent devices.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217328
Link: https://bugs.debian.org/1033058
Fixes: 241d2fb5 ("of: Make OF framebuffer device names unique")
Cc: stable@vger.kernel.org
Cc: Cyril Brulebois <cyril@debamax.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Helge Deller <deller@gmx.de>
Acked-by: Helge Deller <deller@gmx.de>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Michal Suchánek <msuchanek@suse.de>
Link: https://lore.kernel.org/r/20230710174007.2291013-1-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/platform.c

@@ -552,7 +552,7 @@ static int __init of_platform_default_populate_init(void)
 			if (!of_get_property(node, "linux,opened", NULL) ||
 			    !of_get_property(node, "linux,boot-display", NULL))
 				continue;
-			dev = of_platform_device_create(node, "of-display.0", NULL);
+			dev = of_platform_device_create(node, "of-display", NULL);
 			of_node_put(node);
 			if (WARN_ON(!dev))
 				return -ENOMEM;