drm/exynos: fimd: don't set .has_hw_trigger in s3c6400 driver data

The field value is only checked in fimd_setup_trigger() if .trg_type is
I80_HW_TRG so there's no point in setting this field for the s3c6400 if
is never going to be used since .trg_type is not set.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>