MAINTAINERS: Remove reference to non-existing file

GPIO HiSilicon driver doesn't provide any platform data header.

Fixes: a8f2523 ("MAINTAINERS: Add maintainer for HiSilicon GPIO driver")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20201214165524.43843-2-andriy.shevchenko@linux.intel.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: andy-shev

MAINTAINERS

@@ -7913,7 +7913,6 @@ M:	Luo Jiaxing <luojiaxing@huawei.com>
 L:	linux-gpio@vger.kernel.org
 S:	Maintained
 F:	drivers/gpio/gpio-hisi.c
-F:	include/linux/platform_data/gpio-hisi.h
 
 HISILICON HIGH PERFORMANCE RSA ENGINE DRIVER (HPRE)
 M:	Zaibo Xu <xuzaibo@huawei.com>