drm/exynos: removed meaningless parameter from fbdev update

drm_framebuffer already has width and height so they are meaningless as
parameters when updating fb_info.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>