virt.cfg: adjust Ubuntu preseed grub cmdline

When booting into single-user mode only the first console in the
list will actually show a prompt. This lead to issues with a few of
the qemu tests. Switch the order so the proper terminal shows a prompt
in single user mode.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
guest-os: Ubuntu*.preseed add additional packages

Add additional base packages to enable tp-qemu test cases.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
guest-os: Ubuntu.cfg change cpu_chk_cmd

The old style of command causes issues because of the $ character in
Ubuntu environments causing tests to fail. Replace with a safer command.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
cfg.base: change default profiler to perf for Ubuntu

Ubuntu and Debian do not package kvm_stat; this changes the base
profiler to perf which is available.

Signed-off-by: Chris J Arges <chris.j.arges@canonical.com>
Merge pull request #1829 from arges/ubuntu

Fixes for Ubuntu guests