drm/exynos: cleanup function calling written twice

By if statment, some function callings are written twice. It needs
several line feed by indentation in if statment. Make to one function
calling from outside if statment.

Signed-off-by: Joonyoung Shim <jy0922.shim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>