target/arm: Use the max page size in a 2-stage ptw

target/arm: Use the max page size in a 2-stage ptw

We had only been reporting the stage2 page size.  This causes
problems if stage1 is using a larger page size (16k, 2M, etc),
but stage2 is using a smaller page size, because cputlb does
not set large_page_{addr,mask} properly.

Fix by using the max of the two page sizes.

Reported-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20221024051851.3074715-15-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>