dri2: Set fallback driver names for Intel and AMD chips

i965 and radeonsi, respectively, are the drivers that have been
receiving new hardware support. It's really silly to need to update the
server side to know specific new devices IDs every time a new ASIC comes
out.

Reviewed-by: Michel Dänzer <mdaenzer@redhat.com>
3 jobs for dri2-driver-fallbacks in 4 minutes and 51 seconds (queued for 9 minutes and 47 seconds)
Status Job ID Name Coverage
  Docker Image
passed #679955
debian-testing

00:00:20

 
  Build And Test
passed #679956
autotools-build-and-test

00:04:30

passed #679957
meson-build-and-test

00:01:40