gpu: Select default driver

Improve default driver selection by checking the available DRM devices
instead of the supported device names list.

Signed-off-by: Antonio Caggiano <antonio.caggiano@collabora.com>
3 jobs for tintou/one-driver in 56 seconds (queued for 1 second)
Status Job ID Name Coverage
  Check
passed #8624060
clang-format

00:00:45

 
  Build
canceled #8624062
aarch64
aarch64

00:00:11

canceled #8624061
kvm
x86_64

00:00:11