gpio: mockup: tweak the Kconfig help text

gpio-mockup doesn't require SYSFS to be selected so drop that bit from
the Kconfig text.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
1 file changed