In order to detect it at runtime, we need the code handling wdt
clock available at runtime to decide whether to enable or disable
based on the baseimage symbols. Default timeout has been set to 5
seconds.

Downside is that we will lose the option to set a custom timeout
for overflow, but than can be added (if needed) as part of debugfs.
Signed-off-by: Omar Ramirez <omar.ramirez@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>