arm/ptw: Make get_S1prot accept decoded AP

arm/ptw: Make get_S1prot accept decoded AP

AP in armv7 short descriptor mode has 3 bits and also domain, which
makes it incompatible with other arm schemas.

To make it possible to share get_S1prot between armv8, armv7 long
format, armv7 short format and armv6 it's easier to make caller
decode AP.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Message-id: 20241118152526.45185-1-paskripkin@gmail.com
[PMM: fixed checkpatch nit]
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>