fbdev: ssd1307fb: Init backlight before registering framebuffer

fbdev: ssd1307fb: Init backlight before registering framebuffer

For drivers that support backlight, LCD and fbdev devices, fbdev has
to be initialized last. See documentation for struct fbinfo.bl_dev.

The backlight name's index number comes from register_framebuffer(),
which now happens after initializing the backlight device. So like
in all other backlight drivers, we now give the backlight device a
generic name without the fbdev index.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://lore.kernel.org/r/20240305162425.23845-9-tzimmermann@suse.de
Signed-off-by: Lee Jones <lee@kernel.org>