sdhci: don't assign mmc->caps at SDHCI directly

Some host controllers can set mmc->caps before sdhci_add_host().

Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Grant Likely <grant.likely@secretlab.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index f34ec5d..3896069 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -1797,7 +1797,7 @@
 	else
 		mmc->f_min = host->max_clk / 256;
 	mmc->f_max = host->max_clk;
-	mmc->caps = MMC_CAP_SDIO_IRQ;
+	mmc->caps |= MMC_CAP_SDIO_IRQ;
 
 	if (!(host->quirks & SDHCI_QUIRK_FORCE_1_BIT_DATA))
 		mmc->caps |= MMC_CAP_4_BIT_DATA;