hw/riscv: Widen OpenSBI dynamic info struct

hw/riscv: Widen OpenSBI dynamic info struct

Since fw_dynamic_info is only used for non 32 bit targets, target_long
is int64_t anyway.  Rename struct to fw_dynamic_info64 and use int64_t.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Anton Johansson <anjo@rev.ng>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20251027-feature-single-binary-hw-v1-v2-3-44478d589ae9@rev.ng>
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>