The code in cpu_mmu_index does not properly honor SR_DME.
This bug has workarounds elsewhere in that we flush the
tlb more often than necessary, on the state changes that
should be reflected in a change of mmu_index.
Fixing this means that we can respect the mmu_index that
is given to tlb_flush.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Stafford Horne <shorne@gmail.com>