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>
1 file changed