We were overriding values from `gamecontrollerdb.txt` (current, updated
upstream) with `gamecontrollerdb_205.txt` (legacy, SDL 2.0.5) and then
`gamecontrollerdb_204.txt` (legacy, SDL 2.0.4).

There was a comment to warn about this but it seems it did not prevent
using the wrong order for all this time...

Now `gamecontrollerdb.txt` mappings will properly override outdated
ones present in the `204` and `205` variants.