mmc: bfin_sdh: limit mmc DMA segment len to 1 for bf518.

bf518 RSI dma doesn't work in array mode.
Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/bfin_sdh.c

@@ -462,7 +462,11 @@ static int __devinit sdh_probe(struct platform_device *pdev)
 	}
 
 	mmc->ops = &sdh_ops;
+#if defined(CONFIG_BF54x)
 	mmc->max_segs = 32;
+#elif defined(CONFIG_BF51x)
+	mmc->max_segs = 1;
+#endif
 	mmc->max_seg_size = 1 << 16;
 	mmc->max_blk_size = 1 << 11;
 	mmc->max_blk_count = 1 << 11;