hw/riscv/virt: Fix clint base address type

hw/riscv/virt: Fix clint base address type

The address is a hardware address, so use hwaddr for consistency with
the rest of the machine.

Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Message-ID: <20250604025450.85327-2-joel@jms.id.au>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>