exynos: Update to use new api to ion_client_create

This change updates the exynos video drivers to use the new
ion_client_create call that removed the unused heapmask field.

Change-Id: I27bf7ee45753bf58e418f852e123071a7d1b333a
Signed-off-by: Rebecca Schultz Zavin <rebecca@android.com>
Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>