MIPS: ingenic: DTS: Fix watchdog nodes

The devicetree ABI was broken on purpose by commit 6d532143
("watchdog: jz4740: Use regmap provided by TCU driver"), and
commit 1d9c3074 ("watchdog: jz4740: Use WDT clock provided
by TCU driver"). The commit message of the latter explains why the ABI
was broken.

However, the current devicetree files were not updated to the new ABI
described in Documentation/devicetree/bindings/timer/ingenic,tcu.txt,
so the watchdog driver would not probe.

Fix this problem by updating the watchdog nodes to comply with the new
ABI.

Fixes: 6d532143 ("watchdog: jz4740: Use regmap provided by TCU driver")
Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paul Burton <paulburton@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Zhou Yanjie <zhouyanjie@wanyeetech.com>
Cc: od@zcrc.me
Cc: linux-mips@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: <stable@vger.kernel.org> # v5.5+