Add 'console=tty0 quiet' to cmdline for aarch64 installs
We need this as part of the fix for #1593028, at least until
the kernel package is changed to no longer have
CONFIG_CMDLINE="console=ttyAMA0" in the config for aarch64
builds. Fully fixing the bug also requires some change to the
kernel or dracut or something.
Signed-off-by: Adam Williamson <awilliam@redhat.com>