target/arm: Introduce ARMMMUIdx_Phys_{Realm,Root}

target/arm: Introduce ARMMMUIdx_Phys_{Realm,Root}

With FEAT_RME, there are four physical address spaces.
For now, just define the symbols, and mention them in
the same spots as the other Phys indexes in ptw.c.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230620124418.805717-9-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>