fbdev/offb: Update expected device name

fbdev/offb: Update expected device name

Origin: https://git.kernel.org/pub/scm/linux/kernel/git/deller/linux-fbdev.git/commit?id=27c74ea74be805ccba1bc1a0a03cc79c51dca6ea

Since commit 241d2fb56a18 ("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.

It might be better to iterate on all possible nodes, but updating the
hardcoded device from "of-display" to "of-display.0" is confirmed to fix
the Debian Installer at the very least.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=217328
Link: https://bugs.debian.org/1033058
Fixes: 241d2fb56a18 ("of: Make OF framebuffer device names unique")
Cc: stable@vger.kernel.org
Signed-off-by: Cyril Brulebois <cyril@debamax.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Gbp-Pq: Topic bugfix/powerpc
Gbp-Pq: Name fbdev-offb-Update-expected-device-name.patch