This is effectively the closure of the ioctl handler table in
radeon_cp.c. That ioctl table is unused (we use the radeon_kms ioctl
table instead), so there is no way for any of the functions referenced
by the table to be called.

This was motivated by a report of an integer overflow vulnerability in
r600_cp_dispatch_texture() (the multiplication of tex->height and
tex->pitch, which are user-controlled). However, I believe the code
in question cannot get invoked.

I verified that radeonkms.ko still loads (i.e., no missing symbols).

Initially, my test was to simply comment out the radeon_ioctls[] table
and kldload, verifying that the ioctl handlers are indeed dead code.