MIPS: JZ4780: dts: Fix watchdog node

- The previous node requested a memory area of 0x100 bytes, while the
  driver only manipulates four registers present in the first 0x10 bytes.

- The driver requests for the "rtc" clock, but the previous node did not
  provide any.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Mathieu Malaterre <malat@debian.org>
Acked-by: James Hogan <jhogan@kernel.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Mathieu Malaterre <malat@debian.org>
Cc: linux-mips@linux-mips.org
Cc: devicetree@vger.kernel.org
Cc: linux-watchdog@vger.kernel.org
Signed-off-by: James Hogan <jhogan@kernel.org>