hw/misc/sifive_u_otp: Remove the deprecated OTP config with '-drive if=none'

'-drive if=none' is meant for configuring back-end devices only, so this
got marked as deprecated in QEMU 6.2. Users should now only use the new
way with '-drive if=pflash' instead.

Message-Id: <20230112083921.887828-1-thuth@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>
3 files changed