firmware: google: framebuffer: Do not unregister platform device

firmware: google: framebuffer: Do not unregister platform device

The native driver takes over the framebuffer aperture by removing the
system- framebuffer platform device. Afterwards the pointer in drvdata
is dangling. Remove the entire logic around drvdata and let the kernel's
aperture helpers handle this. The platform device depends on the native
hardware device instead of the coreboot device anyway.

When commit 851b4c14532d ("firmware: coreboot: Add coreboot framebuffer
driver") added the coreboot framebuffer code, the kernel did not support
device-based aperture management. Instead native driviers only removed
the conflicting fbdev device. At that point, unregistering the framebuffer
device most likely worked correctly. It was definitely broken after
commit d9702b2a2171 ("fbdev/simplefb: Do not use struct
fb_info.apertures"). So take this commit for the Fixes tag. Earlier
releases might work depending on the native hardware driver.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Fixes: d9702b2a2171 ("fbdev/simplefb: Do not use struct fb_info.apertures")
Acked-by: Tzung-Bi Shih <tzungbi@kernel.org>
Acked-by: Julius Werner <jwerner@chromium.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Cc: Hans de Goede <hansg@kernel.org>
Cc: linux-fbdev@vger.kernel.org
Cc: <stable@vger.kernel.org> # v6.3+
Link: https://patch.msgid.link/20260217155836.96267-2-tzimmermann@suse.de