Revert "videobuf2-dma-contig: Only support if HAVE_GENERIC_DMA_COHERENT"

The right solution is to remove the architecture dependency on
dma_common_get_sgtable(). Revert this patch to apply the right one.

This reverts commit 93049b9368a2e257ace66252ab2cc066f3399cad.

drivers/media/v4l2-core/videobuf2-dma-contig.c

@@ -226,8 +226,6 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma)
 /*         DMABUF ops for exporters          */
 /*********************************************/
 
-#ifdef HAVE_GENERIC_DMA_COHERENT
-
 struct vb2_dc_attachment {
 	struct sg_table sgt;
 	enum dma_data_direction dir;
@@ -418,8 +416,6 @@ static struct dma_buf *vb2_dc_get_dmabuf(void *buf_priv)
 	return dbuf;
 }
 
-#endif
-
 /*********************************************/
 /*       callbacks for USERPTR buffers       */
 /*********************************************/
@@ -739,9 +735,7 @@ static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf,
 const struct vb2_mem_ops vb2_dma_contig_memops = {
 	.alloc		= vb2_dc_alloc,
 	.put		= vb2_dc_put,
-#ifdef CONFIG_HAVE_GENERIC_DMA_COHERENT
 	.get_dmabuf	= vb2_dc_get_dmabuf,
-#endif
 	.cookie		= vb2_dc_cookie,
 	.vaddr		= vb2_dc_vaddr,
 	.mmap		= vb2_dc_mmap,