watchdog: support a default interval parameter

IBM has a desire to be able to define a Interval value different then
the default on watchdog startup. Some systems need a larger starting
value and it's easiest to pass this in at watchdog startup time.

Tested:
- Verified when new parameter is not passed, the standard 30000 default
  is used.
- Verified when the new --default_interval is passed in that it is used

Signed-off-by: Andrew Geissler <geissonator@yahoo.com>
Change-Id: I51908f69b4f9af26a7bb49101c4ca2ee97ef555c
2 files changed