const-ify the font control structures and data, to make somewhat better
guarantees that these are not modified anywhere in the kernel.
Specifically for a kernel debugger to share this information from the
normal kernel code, such a guarantee seems rather desirable.

Signed-off-by: Jan Beulich
Cc: "Antonino A. Daplas"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds