target/arm: Consider GP an attribute in get_phys_addr_lpae

target/arm: Consider GP an attribute in get_phys_addr_lpae

Both GP and DBM are in the upper attribute block.
Extend the computation of attrs to include them,
then simplify the setting of guarded.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-id: 20221024051851.3074715-11-richard.henderson@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>