omapfb: dss: Do not duplicate features data

As features data are read only, there is no need to allocate their
copy on the heap.

Suggested-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Ladislav Michl <ladis@linux-mips.org>
Tested-by: Adam Ford <aford173@gmail.com> #omap3630
Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Arvind Yadav <arvind.yadav.cs@gmail.com>
Cc: Markus Elfring <elfring@users.sourceforge.net>
Cc: Peter Ujfalusi <peter.ujfalusi@ti.com>
Cc: Adam Ford <adam.ford@logicpd.com>
[b.zolnierkie: fixed minor CodingStyle errors reported by checkpatch.pl]
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>