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.