mmc: meson-gx: reduce bounce buffer size

A bounce buffer of 512K isn't needed as the max request size is
511 * 512 byte.

Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Kevin Hilman <khilman@baylibre.com>
Tested-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/meson-gx-mmc.c

@@ -782,7 +782,7 @@ static int meson_mmc_probe(struct platform_device *pdev)
 	mmc->max_req_size = mmc->max_blk_count * mmc->max_blk_size;
 
 	/* data bounce buffer */
-	host->bounce_buf_size = SZ_512K;
+	host->bounce_buf_size = mmc->max_req_size;
 	host->bounce_buf =
 		dma_alloc_coherent(host->dev, host->bounce_buf_size,
 				   &host->bounce_dma_addr, GFP_KERNEL);