s3c2410fb: make use of default_display settings

This patch changes mode selection to always prefer default mode if possible
and always honor type of display set by default mode settings.

This patch is required in case the same display modes were defined for
different panels (e.g.  STN and TFT).

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>