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>

include/hw/watchdog/wdt_imx2.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2017, Impinj, Inc.
+ *
+ * i.MX2 Watchdog IP block
+ *
+ * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#ifndef IMX2_WDT_H
+#define IMX2_WDT_H
+
+#include "hw/sysbus.h"
+
+#define TYPE_IMX2_WDT "imx2.wdt"
+#define IMX2_WDT(obj) OBJECT_CHECK(IMX2WdtState, (obj), TYPE_IMX2_WDT)
+
+enum IMX2WdtRegisters {
+    IMX2_WDT_WCR     = 0x0000,
+    IMX2_WDT_REG_NUM = 0x0008 / sizeof(uint16_t) + 1,
+};
+
+
+typedef struct IMX2WdtState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    MemoryRegion mmio;
+} IMX2WdtState;
+
+#endif /* IMX2_WDT_H */