hw/riscv: Fix integer overflow in cm_base calculation Ensure 64-bit arithmetic is used when computing cm_base, avoiding potential integer overflow. Resolves: Coverity CID 1644076 Signed-off-by: Djordje Todorovic <djordje.todorovic@htecgroup.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-ID: <20260115130110.2825796-2-djordje.todorovic@htecgroup.com> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>