target/arm: Enhance CPU_LOG_INT to show SPSR on AArch64 exception-entry

target/arm: Enhance CPU_LOG_INT to show SPSR on AArch64 exception-entry

We already print various lines of information when we take an
exception, including the ELR and (if relevant) the FAR. Now
that FEAT_NV means that we might report something other than
the old PSTATE to the guest as the SPSR, it's worth logging
this as well.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Miguel Luis <miguel.luis@oracle.com>