ramips: gdma: remove slave_id field

Fix compile error:
drivers/dma/ralink-gdma.c: In function 'gdma_dma_config':
drivers/dma/ralink-gdma.c:197:40: error: 'struct dma_slave_config' has no member named 'slave_id'
  197 |                 chan->slave_id = config->slave_id;
      |                                        ^~
drivers/dma/ralink-gdma.c:206:40: error: 'struct dma_slave_config' has no member named 'slave_id'
  206 |                 chan->slave_id = config->slave_id;
      |                                        ^~
make[8]: *** [scripts/Makefile.build:243: drivers/dma/ralink-gdma.o] Error 1

ref: https://lore.kernel.org/all/[email protected]/

Signed-off-by: Shiji Yang <[email protected]>

target/linux/ramips/files/drivers/dma/ralink-gdma.c

@@ -194,7 +194,6 @@ static int gdma_dma_config(struct dma_chan *c,
 			dev_err(dma_dev->ddev.dev, "only support 4 byte buswidth\n");
 			return -EINVAL;
 		}
-		chan->slave_id = config->slave_id;
 		chan->fifo_addr = config->dst_addr;
 		chan->burst_size = gdma_dma_maxburst(config->dst_maxburst);
 		break;
@@ -203,7 +202,6 @@ static int gdma_dma_config(struct dma_chan *c,
 			dev_err(dma_dev->ddev.dev, "only support 4 byte buswidth\n");
 			return -EINVAL;
 		}
-		chan->slave_id = config->slave_id;
 		chan->fifo_addr = config->src_addr;
 		chan->burst_size = gdma_dma_maxburst(config->src_maxburst);
 		break;