This patch adds an emulation for the LSI Megaraid SAS 8708EM2 HBA.
I've tested it to work with Linux, Windows Vista, and Windows7.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[ Squashed trivial changes from Andreas Faerber, rebased over IOMMU
  and QBus changes - Paolo ]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>