agp: Make the legacy AGP interface optional

The only thing using this anymore is the i810 driver, so this can safely
be disabled on non-i686 builds.

Signed-off-by: Adam Jackson <ajax@redhat.com>
2 jobs for optional-agp in 1 minute and 15 seconds
Status Name Job ID Coverage
  Docker Image
passed debian-testing #82972

00:00:23

 
  Build And Test
passed build-and-test #82973

00:00:52