hw: Move i.MX watchdog driver to hw/watchdog

In preparation for a full implementation, move i.MX watchdog driver
from hw/misc to hw/watchdog. While at it, add the watchdog files
to MAINTAINERS.

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Message-id: 20200517162135.110364-2-linux@roeck-us.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
10 files changed