target/arm: Extract TCG -cpu max code into a function

target/arm: Extract TCG -cpu max code into a function

Introduce aarch64_max_tcg_initfn that contains the TCG-only part of
-cpu max configuration. We'll need that to be able to restrict this
code to a TCG-only config in the next patches.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Fabiano Rosas <farosas@suse.de>
Message-id: 20230426180013.14814-4-farosas@suse.de
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>