[drbcc-wd] Added routine for setting timeout

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>
[darbcc-wd] Edited comment

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>
[drbcc-wd] Renamed registered watchdog

Renamed from "drbcc-watchdog" to "watchdog", since this is the device which is addressed as a default by the watchdog tools.

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>
[darmok-wd] Ioctl WDIOC_KEEPALIVE command implemented

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>
[drbcc-wd] Added open, close and IOCTL function

Furthermore there is a function for switching between kernel driver and userspace operated ping of the watchdog.
Known (but possibly not fully implemented) IOCTL calls:
* WDIOC_SETOPTIONS
* WDIOS_DISABLECARD
* WDIOS_ENABLECARD
* WDIOC_KEEPALIVE
* WDIOC_SETTIMEOUT
* WDIOC_GETTIMEOUT

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>
[drbcc-wd] Added timer for kicking the watchdog

Signed-off-by: Christina Quast <chrysh.ng+github@gmail.com>