target/arm: Move e2h_access() helper around

target/arm: Move e2h_access() helper around

e2h_access() was added in commit bb5972e439 ("target/arm:
Add VHE timer register redirection and aliasing") close to
the generic_timer_cp_reginfo[] array, but isn't used until
vhe_reginfo[] definition. Move it closer to the other e2h
helpers.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20240118200643.29037-19-philmd@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>