MAINTAINERS: Add entries for Toshiba Visconti5 watchdog driver

Add entries for Toshiba Visconti5 watchdog driver and binding.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>

MAINTAINERS

@@ -2643,8 +2643,10 @@ S:	Supported
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/iwamatsu/linux-visconti.git
 F:	Documentation/devicetree/bindings/arm/toshiba.yaml
 F:	Documentation/devicetree/bindings/pinctrl/toshiba,tmpv7700-pinctrl.yaml
+F:	Documentation/devicetree/bindings/watchdog/toshiba,visconti-wdt.yaml
 F:	arch/arm64/boot/dts/toshiba/
 F:	drivers/pinctrl/visconti/
+F:	drivers/watchdog/visconti_wdt.c
 N:	visconti
 ARM/UNIPHIER ARCHITECTURE