target/ppc: change ppc_hash32_xlate to use mmu_idx

target/ppc: change ppc_hash32_xlate to use mmu_idx

Changed hash32 address translation to use the supplied mmu_idx, instead
of using what was stored in the msr, for parity purposes (radix64
already uses that) and for conceptual correctness, all the relevant
functions should always use the supplied mmu_idx, as there are no
guarantees that the mmu_idx stored in the CPU variable will not desync.

Signed-off-by: Bruno Larsen (billionai) <bruno.larsen@eldorado.org.br>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20210706150316.21005-3-bruno.larsen@eldorado.org.br>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>