hw/arm/virt: smbios: inform guest of kvm

ARM/AArch64 KVM guests don't have any way to identify
themselves as KVM guests (x86 guests use a CPUID leaf). Now, we
could discuss all sorts of reasons why guests shouldn't need to
know that, but then there's always some case where it'd be
nice... Anyway, now that we have SMBIOS tables in ARM guests,
it's easy for the guest to know that it's a QEMU instance. This
patch takes that one step further, also identifying KVM, when
appropriate. Again, we could debate why generally nothing
should care whether it's of type QEMU or QEMU/KVM, but again,
sometimes it's nice to know...

Signed-off-by: Andrew Jones <drjones@redhat.com>
Reviewed-by: Wei Huang <wei@redhat.com>
Message-id: 1443017892-15567-1-git-send-email-drjones@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>