target/ppc: Enable RADIX mmu mode for pseries TCG guest

target/ppc: Enable RADIX mmu mode for pseries TCG guest

Now that we have added all the infrastructure we can enable a pseries TCG
guest to use radix.

In order to do this we have to add the appropriate bits to the
ibm,arch-vec-5-platform-support vector to represent that we support both
hash and radix mmu models.

A radix guest can now be booted in pseries tcg mode by specifying:
-cpu POWER9

Note that we assume hash, that is we allocate a hpt, until a guest tells
us otherwise via a H_REGISTER_PROCESS_TABLE call with radix specified - in
which case we free the hpt. If we were right and the guest is hash then
there's nothing for us to do.

Signed-off-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>