exynos4/4x12: gpio: use gpio extra base addresses

This patch adds extra gpio part addresses to exynos4
and exynos4x12_gpio_data arrays, which are required
since the gpio enum lists are linear

Signed-off-by: Przemyslaw Marczak <p.marczak@samsung.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>