target/arm: make arm_casq_ptw CONFIG_TCG only

target/arm: make arm_casq_ptw CONFIG_TCG only

The ptw code is accessed by non-TCG code (specifically arm_pamax and
arm_cpu_get_phys_page_attrs_debug) but most of it is really only for
TCG emulation. Seeing as we already assert for a non TARGET_AARCH64
build lets extend the test rather than further messing with the ifdef
ladder.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20230630180423.558337-19-alex.bennee@linaro.org>