watchdog: convert drivers/watchdog/* to use module_platform_driver()

This patch converts the drivers in drivers/watchdog/* to use the
module_platform_driver() macro which makes the code smaller and a bit
simpler.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Nicolas Thill <nico@openwrt.org>
Cc: Florian Fainelli <florian@openwrt.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Marc Zyngier <maz@misterjones.org>
Cc: Wan ZongShun <mcuos.com@gmail.com>
Cc: Alejandro Cabrera <aldaya@gmail.com>
Cc: "George G. Davis" <gdavis@mvista.com>
Cc: Sylver Bruneau <sylver.bruneau@googlemail.com>
Cc: Vitaly Wool <vital@embeddedalley.com>
Cc: Mika Westerberg <mika.westerberg@iki.fi>
Cc: Timo Kokkonen <timo.t.kokkonen@nokia.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

diff --cc drivers/watchdog/ar7_wdt.c
Simple merge

diff --cc drivers/watchdog/bcm63xx_wdt.c
Simple merge

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

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

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

diff --cc drivers/watchdog/jz4740_wdt.c
Simple merge

diff --cc drivers/watchdog/max63xx_wdt.c
Simple merge

diff --cc drivers/watchdog/mtx-1_wdt.c
Simple merge

diff --cc drivers/watchdog/nuc900_wdt.c
Simple merge

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

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

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

diff --cc drivers/watchdog/pnx4008_wdt.c
Simple merge

diff --cc drivers/watchdog/rc32434_wdt.c
Simple merge

diff --cc drivers/watchdog/rdc321x_wdt.c
Simple merge

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

diff --cc drivers/watchdog/stmp3xxx_wdt.c
Simple merge

diff --cc drivers/watchdog/ts72xx_wdt.c
Simple merge

diff --cc drivers/watchdog/twl4030_wdt.c
Simple merge