Fix the watchdog/watchdog man pages.

The default timeout is 128 seconds.

MFC after:	1 week
AM335x FDT: add an entry for the watchdog.

MFC after:	1 week
Disable hyperv on pc98.
Merge remote-tracking branch 'freebsd/master' into hardened/current/master
Merge remote-tracking branch 'origin/hardened/current/master' into hardened/current/segvguard