keyguard: force marquee effect for carrier text

This allows to make rooms for languages with long carrier text descriptions.

Change-Id: I8a3f69d186e79971c66c4977d258b2bda48ceeff
JIRA: CYAN-4356
Issue: https://jira.cyanogenmod.org/browse/CYAN-4356
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>