Cluster support fixes

Cluster support fixes

Changes:
- Rename CLUSTER_DEMO_VISS_HOSTNAME to CLUSTER_DEMO_VSS_HOSTNAME
  since we're not using VISS at this point.
- Change TRANSMITTER_OUTPUT_HOST to REMOTING_OUTPUT_HOST in KVM
  demo configuration to match change previously made in the
  weston-ini-conf recipe in meta-agl.

Bug-AGL: SPEC-5086

Change-Id: Id5a7ab5fab9b19786b4eeb743a06c71693e0a0da
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl-demo/+/29703
Tested-by: Jenkins Job builder account
ci-image-build: Jenkins Job builder account
ci-image-boot-test: Jenkins Job builder account
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>