MAINTAINERS: gpio: vt8500: Remove file pattern

commit dc101086 ("gpio: vt8500: Remove arch-vt8500 gpio driver")
removed the file, remove the pattern.

Signed-off-by: Joe Perches <joe@perches.com>
cc: Tony Prisk <linux@prisktech.co.nz>
cc: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>