staging: comedi: addi_apci_1516: fix i_APCI1516_ConfigWatchdog()

This function is used by the watchdog subdevice to enable/disable and
set the timeout for the watchdog. Rename the CamelCase function to
apci1516_wdog_insn_config.

Currently this function does not follow the comed API. Recode it so
it works like the core expects. data[0] is the configuration id code
(INSN_CONFIG_*) for the configuration instruction. Two instructions
are supported:

INSN_CONFIG_ARM: enables the watchdog and sets the timeout value
INSN_CONFIG_DISARM: disables the watchdog

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>