OMAP: DSS2: OMAPFB: Fix probe error path

Move sysfs entry creation to omapfb_probe() from omapfb_create_framebuffers().
This will make sure that sysfs entry is not left behind in case of unsuccessful
probe due to failure in enabling fb0 of omapfb_create_framebuffers().

Signed-off-by: Afzal Mohammed <lazfamam@gmail.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>