watchdog: remove w90x900 driver

The ARM w90x900 platform is getting removed, so this driver is obsolete

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20190809202749.742267-7-arnd@arndb.de
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>

Documentation/watchdog/watchdog-parameters.rst

@@ -366,16 +366,6 @@ nic7018_wdt:
 
 -------------------------------------------------
 
-nuc900_wdt:
-    heartbeat:
-	Watchdog heartbeats in seconds.
-	(default = 15)
-    nowayout:
-	Watchdog cannot be stopped once started
-	(default=kernel config parameter)
-
--------------------------------------------------
-
 omap_wdt:
     timer_margin:
 	initial watchdog timeout (in seconds)