WATCHDOG: octeon-wdt: Use I/O clock rate for timing calculations.

WATCHDOG: octeon-wdt: Use I/O clock rate for timing calculations.

The creation of the I/O clock domain requires some adjustments.  Since
the watchdog counters are clocked by the I/O clock, use its rate for
timing calculations.

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
Cc: Wim Van Sebroeck <wim@iguana.be>
Cc: linux-watchdog@vger.kernel.org
Patchwork: http://patchwork.linux-mips.org/patch/1659/
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>