configure.ac: use a single require_libdrm helper

Rather than having 4-5 places which do the explicit check/message just
polish the gallium helper and use it everywhere.

Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Axel Davy <axel.davy@ens.fr>
Reviewed-by: Nicolai Hähnle <nicolai.haehnle@amd.com>
1 file changed