dmaengine: xilinx: vdma: Allow only one chunk in a line

This patch adds a sanity check to see if frame_size is 1.

Signed-off-by: Srikanth Thokala <sthokal@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/xilinx/xilinx_vdma.c b/drivers/dma/xilinx/xilinx_vdma.c
index 1093794..3d3f70d 100644
--- a/drivers/dma/xilinx/xilinx_vdma.c
+++ b/drivers/dma/xilinx/xilinx_vdma.c
@@ -942,6 +942,9 @@
 	if (!xt->numf || !xt->sgl[0].size)
 		return NULL;
 
+	if (xt->frame_size != 1)
+		return NULL;
+
 	/* Allocate a transaction descriptor. */
 	desc = xilinx_vdma_alloc_tx_descriptor(chan);
 	if (!desc)