monitor/hmp-cmds: Use cpu_translate_for_debug()

We want to remove the cpu_get_phys_addr_debug() function; update the
HMP gva2gpa command implementation to use cpu_translate_for_debug()
instead.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20260430093810.2762539-24-peter.maydell@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>