target/riscv: Move insn_len to internals.h

target/riscv: Move insn_len to internals.h

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Message-ID: <20250425152311.804338-7-richard.henderson@linaro.org>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>