accel/ethosu: reject NPU_OP_RESIZE commands from userspace

In the Linux kernel, the following vulnerability has been resolved: accel/ethosu: reject NPU_OP_RESIZE commands from userspace NPU_OP_RESIZE is a U85-only command that the driver does not yet implement. The existing WARN_ON(1) placeholder fires unconditionally whenever userspace submits this command via DRM_IOCTL_ETHOSU_GEM_CREATE, causing unbounded kernel log spam. If panic_on_warn is set the kernel panics, giving any unprivileged user with access to the DRM device a trivial denial-of-service primitive. Replace the WARN_ON(1) with an explicit -EINVAL return so the ioctl rejects the command before it reaches hardware.