hw/mips/loongson3_virt: Pass CPU argument to get_cpu_freq_hz()

Pass the first vCPU as argument, allowing to remove
another &first_cpu global use.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20250115232952.31166-5-philmd@linaro.org>
1 file changed