Fix missing kernel output via VNC/Spice on boot

Bug 1164021

Use both ttys0 and tty0 as console options to the kernel during
boot.

Change-Id: I0365ff7cad021fb6ca551651d00d58297087e95e
(cherry picked from commit b980de7cd1ac0e9085c20392bf82d1d3b12b24e8)
Merge "Fix missing kernel output via VNC/Spice on boot" into stable/grizzly