watchdog: remove empty pm-functions

While checking what watchdog drivers usually do in suspend/resume to
spot common behaviour for the watchdog framework, I found these drivers
which do nothing but add some cruft. Remove it, it is superfluous. New
approaches should probably be done with pm_ops anyway.

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --cc drivers/watchdog/at91sam9_wdt.c
Simple merge

diff --cc drivers/watchdog/iTCO_wdt.c
Simple merge

diff --cc drivers/watchdog/sch311x_wdt.c
Simple merge