[media] bdisp: prevent compiling on random arch

This driver requires support for DMA attrs function, and not
just DMA. Change the options accordingly to remove those errors:

/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c: In function ‘bdisp_hw_free_nodes’:
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c:132:3: error: implicit declaration of function ‘dma_free_attrs’ [-Werror=implicit-function-declaration]
   dma_free_attrs(ctx->bdisp_dev->dev,
   ^
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c: In function ‘bdisp_hw_alloc_nodes’:
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c:157:9: error: implicit declaration of function ‘dma_alloc_attrs’ [-Werror=implicit-function-declaration]
  base = dma_alloc_attrs(dev, node_size * MAX_NB_NODE, &paddr,
         ^
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c:157:7: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
  base = dma_alloc_attrs(dev, node_size * MAX_NB_NODE, &paddr,
       ^
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c: In function ‘bdisp_hw_alloc_filters’:
/devel/v4l/to_next/drivers/media/platform/sti/bdisp/bdisp-hw.c:219:7: warning: assignment makes pointer from integer without a cast [-Wint-conversion]
  base = dma_alloc_attrs(dev, size, &paddr, GFP_KERNEL | GFP_DMA, &attrs);

Also, get rid of bogus, unused and duplicated symbol declaration
for the config option done at bdisp/Kconfig.

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>