MMC: AU1xMMC: Allow platforms to disable host capabilities

Although the hardware supports a 4/8bit SD interface and the driver
unconditionally advertises all hardware caps to the MMC core, not all
datalines may actually be wired up.  This patch introduces another
field to au1xmmc platform data allowing platforms to disable certain
advanced host controller features.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
To: linux-mmc@vger.kernel.org
CC: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: http://patchwork.linux-mips.org/patch/460/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/drivers/mmc/host/au1xmmc.c b/drivers/mmc/host/au1xmmc.c
index c8649df..57b2119 100644
--- a/drivers/mmc/host/au1xmmc.c
+++ b/drivers/mmc/host/au1xmmc.c
@@ -1017,6 +1017,10 @@
 	} else
 		mmc->caps |= MMC_CAP_NEEDS_POLL;
 
+	/* platform may not be able to use all advertised caps */
+	if (host->platdata)
+		mmc->caps &= ~(host->platdata->mask_host_caps);
+
 	tasklet_init(&host->data_task, au1xmmc_tasklet_data,
 			(unsigned long)host);