Declarations from "riscv/pmu.h" don't need anything from "qemu/log.h",
reduce it's inclusion to the source.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230828221314.18435-3-philmd@linaro.org>