ARM: SAMSUNG: Remove description corresponding to a deleted element

Commit 3c582647 ("video: s3c-fb: remove 'default_win' element
from platform data") removed the default_win element from the
structure, but the description was not removed.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>