gpio: samsung: fix pinctrl condition for exynos and exynos5440

Since EXYNOS5440 can select PINCTRL_EXYNOS5440 without PINCTRL_SAMSUNG,
it should be fixed. In detail, PINCTRL_SAMSUNG is a kind of frame work
for supporting pinctrl on most Samsung SoCs including S3C, S5P as well
except EXYNOS5440 so PINCTRL_EXYNOS5440 has been implemented separated.

Cc: Thomas Abraham <thomas.ab@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>