MAINTAINERS: Fix Dialog search term for watchdog binding file

Commit 34026764 ("MAINTAINERS: da9062/61 updates to the Dialog
Semiconductor search terms") contained a typo for the watchdog binding:
da92??-wdt.txt should have read da90??-wdt.txt. This new commit will fix
the error and allows Dialog Semiconductor to follow files for PMIC
bindings correctly.
Signed-off-by: Steve Twiss <stwiss.opensource@diasemi.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

MAINTAINERS

@@ -4103,7 +4103,7 @@ F:	Documentation/devicetree/bindings/mfd/da90*.txt
 F:	Documentation/devicetree/bindings/input/da90??-onkey.txt
 F:	Documentation/devicetree/bindings/thermal/da90??-thermal.txt
 F:	Documentation/devicetree/bindings/regulator/da92*.txt
-F:	Documentation/devicetree/bindings/watchdog/da92??-wdt.txt
+F:	Documentation/devicetree/bindings/watchdog/da90??-wdt.txt
 F:	Documentation/devicetree/bindings/sound/da[79]*.txt
 F:	drivers/gpio/gpio-da90??.c
 F:	drivers/hwmon/da90??-hwmon.c