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The ARM w90x900 platform is getting removed, so this driver is obsolete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