target/arm: Add mmu_idx for EL1 and EL2 w/ PAN enabled

target/arm: Add mmu_idx for EL1 and EL2 w/ PAN enabled

To implement PAN, we will want to swap, for short periods
of time, to a different privileged mmu_idx.  In addition,
we cannot do this with flushing alone, because the AT*
instructions have both PAN and PAN-less versions.

Add the ARMMMUIdx*_PAN constants where necessary next to
the corresponding ARMMMUIdx* constant.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20200208125816.14954-3-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>