staging: comedi: s526: remove unused s526_ports array

This array was used to debug dump the registers. The debug
dump has been removed so this array is no longer needed.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>