staging: comedi: addi_apci_3501: cleanup comments in hwdrv_apci3501.c

The watchdog/timer subdevice in this driver is basically broke. The
subdevice functions abuse the comedi API and the (*insn_config)
simply doesn't work due to it's treating data[0] as a parameter and
not as the config "instruction".

For now, cleanup the comments for the functions so they are at least
readable. Then we can figure out how to fix the subdevice.

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>