RedHat: fix announce_device on s390x
RedHat: fix announce_device on s390x

Since the second console used on s390x is sclplm, use the proper device
to communicate back to the host.

Thanks to: Cornelia Huck.

Signed-off-by: Pino Toscano <7f561d60bf2df812acf624afe597ba9d84c2586d@redhat.com>

clalancette/oz,nullr0ute/oz,clalancette/oz,nullr0ute/oz,imcleod/oz,imcleod/oz