target/arm/ptw: Set s1ns bit in fault info more consistently

target/arm/ptw: Set s1ns bit in fault info more consistently

The s1ns bit in ARMMMUFaultInfo is documented as "true if
we faulted on a non-secure IPA while in secure state". Both the
places which look at this bit only do so after having confirmed
that this is a stage 2 fault and we're dealing with Secure EL2,
which leaves the ptw.c code free to set the bit to any random
value in the other cases.

Instead of taking advantage of that freedom, consistently
make the bit be set to false for the "not a stage 2 fault
for Secure EL2" cases. This removes some cases where we
were using an 'is_secure' boolean and leaving the reader
guessing about whether that was the right thing for Realm
and Root cases.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20230807141514.19075-4-peter.maydell@linaro.org