MAINTAINERS: Add Wolfson gpiolib drivers to the Wolfson entry

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

MAINTAINERS

@@ -7578,6 +7578,7 @@ S:	Supported
 F:	Documentation/hwmon/wm83??
 F:	arch/arm/mach-s3c64xx/mach-crag6410*
 F:	drivers/leds/leds-wm83*.c
+F:	drivers/gpio/gpio-*wm*.c
 F:	drivers/hwmon/wm83??-hwmon.c
 F:	drivers/input/misc/wm831x-on.c
 F:	drivers/input/touchscreen/wm831x-ts.c