gpio/samsung: Fix incorrect gpio pull up/down callback for EXYNOS4

Some of the gpio chips of exynos4 are assigned a default gpio config without
the exynos4 specific pull up/down callbacks which resulted in incorrect
setting of pull up/down configuration.

Fix this by adding two new exynos4 specific entries in the array of default
configs with set_pull and get_pull callbacks set to exynos4 specific callbacks
The new default gpio configs can then be used for exynos4 gpio chips.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>