mtd: OneNAND: S5PC110: Fix wrong DMA handling when HIGHMEM

When use HIGHMEM, dma_map_single doesn't get the proper DMA address.
So use the dma_map_page in this case.

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>