watchdog: fix syntactic kernel-doc issues

The command 'find drivers/watchdog | xargs ./scripts/kernel-doc -none'
reports a number of kernel-doc warnings in the watchdog subsystem.

Address the kernel-doc warnings that were purely syntactic issues with
kernel-doc comments.

The remaining kernel-doc warnings are of type "Excess function parameter"
and "Function parameter or member not described". These warnings would
need to be addressed in a second pass with a bit more insight into the
APIs and purpose of the functions in the watchdog subsystem.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20210322065337.617-1-lukas.bulwahn@gmail.com


Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>