media: xilinx: Refactor struct xvip_dma

Replace a single element array with a single field.

The following cocci warning is fixed:
drivers/media/platform/xilinx/xilinx-dma.h:100:19-22: WARNING use flexible-array member instead (https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays)

Signed-off-by: Ricardo Ribalda <[e-mail]>
Reviewed-by: Laurent Pinchart <[e-mail]>
Signed-off-by: Hans Verkuil <[e-mail]>

drivers/media/platform/xilinx/xilinx-dma.c

···
 	}
 
 	dma->xt.frame_size = 1;
-	dma->sgl[0].size = dma->format.width * dma->fmtinfo->bpp;
-	dma->sgl[0].icg = dma->format.bytesperline - dma->sgl[0].size;
+	dma->sgl.size = dma->format.width * dma->fmtinfo->bpp;
+	dma->sgl.icg = dma->format.bytesperline - dma->sgl.size;
 	dma->xt.numf = dma->format.height;
 
 	desc = dmaengine_prep_interleaved_dma(dma->dma, &dma->xt, flags);

drivers/media/platform/xilinx/xilinx-dma.h

···
 	struct dma_chan *dma;
 	unsigned int align;
 	struct dma_interleaved_template xt;
-	struct data_chunk sgl[1];
+	struct data_chunk sgl;
 };
 
 #define to_xvip_dma(vdev)	container_of(vdev, struct xvip_dma, video)