target-ppc: Add versions to server CPU descriptions

target-ppc: Add versions to server CPU descriptions

5b79b1c "target-ppc: Create versionless CPU class per family if KVM" added
a dynamic CPU class registration with the name of the CPU family which
QEMU is running on. For example, this allowed specifying "-cpu POWER7"
on every version of POWER7 machine, not just the one which POWER7 was
an alias of. I.e. before 5b79b1c, "-cpu POWER7" would not work on real
POWER7 2.1 and would work on POWER7 2.3 only. The same story for POWER8.

However that patch broke POWER5+ support as POWER5+ CPU uses the same
name as the CPU class so dynamic registering of the POWER5+ class failed.

This redefines POWER5+ server CPUs by adding a version to them and adding
an alias for TCG case. KVM will use dynamically registered CPUs.

While we are here, do the same for 970 CPU.

Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Alexander Graf <agraf@suse.de>