Unbreak large mem support by removing kqemu

kqemu introduces a number of restrictions on the i386 target.  The worst is that
it prevents large memory from working in the default build.

Furthermore, kqemu is fundamentally flawed in a number of ways.  It relies on
the TSC as a time source which will not be reliable on a multiple processor
system in userspace.  Since most modern processors are multicore, this severely
limits the utility of kqemu.

kvm is a viable alternative for people looking to accelerate qemu and has the
benefit of being supported by the upstream Linux kernel.  If someone can
implement work arounds to remove the restrictions introduced by kqemu, I'm
happy to avoid and/or revert this patch.

N.B. kqemu will still function in the 0.11 series but this patch removes it from
the 0.12 series.

Paul, please Ack or Nack this patch.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
