drm/gma500: Use drm_aperture_remove_conflicting_pci_framebuffers

This one nukes all framebuffers, which is a bit much. In reality
gma500 is igpu and never shipped with anything discrete, so there should
not be any difference.

v2: Unfortunately the framebuffer sits outside of the pci bars for
gma500, and so only using the pci helpers won't be enough. Otoh if we
only use non-pci helper, then we don't get the vga handling, and
subsequent refactoring to untangle these special cases won't work.

It's not pretty, but the simplest fix (since gma500 really is the only
quirky pci driver like this we have) is to just have both calls.

v4:
- fix Daniel's S-o-b address

v5:
- add back an S-o-b tag with Daniel's Intel address

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230406132109.32050-2-tzimmermann@suse.de