dmaengine: Extend the dma_slave_width for 128 bytes

Add DMA_SLAVE_BUSWIDTH_128_BYTES to dma_slave_width for DMA engines
and users to select 128 bytes as bus width.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20210806095322.2326-3-biju.das.jz@bp.renesas.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

include/linux/dmaengine.h

@@ -380,6 +380,7 @@ enum dma_slave_buswidth {
 	DMA_SLAVE_BUSWIDTH_16_BYTES = 16,
 	DMA_SLAVE_BUSWIDTH_32_BYTES = 32,
 	DMA_SLAVE_BUSWIDTH_64_BYTES = 64,
+	DMA_SLAVE_BUSWIDTH_128_BYTES = 128,
 };
 
 /**
@@ -398,7 +399,7 @@ enum dma_slave_buswidth {
  * @src_addr_width: this is the width in bytes of the source (RX)
  * register where DMA data shall be read. If the source
  * is memory this may be ignored depending on architecture.
- * Legal values: 1, 2, 3, 4, 8, 16, 32, 64.
+ * Legal values: 1, 2, 3, 4, 8, 16, 32, 64, 128.
  * @dst_addr_width: same as src_addr_width but for destination
  * target (TX) mutatis mutandis.
  * @src_maxburst: the maximum number of words (note: words, as in