ARM: Export LoUIS flush

Export flushing to LoUIS.

Change-Id: If9e3b7119dd4dbe7bdcf6caee5e1632e77b2c288
Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
Reviewed-on: http://git-master/r/379551
Reviewed-by: Juha Tukkinen <jtukkinen@nvidia.com>