arm64: dts: exynos: Comply to the samsung pinctrl naming convention in TM2

Change the PIN() macro definition so that it can use the macros
from pinctrl/samsung.h header file.

Signed-off-by: Andi Shyti <andi.shyti@samsung.com>
Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>