travis: radeonsi and radv need LLVM 4.0

Fixes: 3bf1e036e8a ("amd: remove support for LLVM 3.9")
Cc: Marek Olšák <marek.olsak@amd.com>
Cc: Emil Velikov <emil.velikov@collabora.com>
Cc: Jan Vesely <jan.vesely@rutgers.edu>
Signed-off-by: Andres Gomez <agomez@igalia.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
1 file changed