mmc: MMC 4.4 DDR support

Add support for Dual Data Rate MMC cards as defined in the 4.4
specification.

Signed-off-by: Hanumath Prasad <hanumath.prasad@stericsson.com>
Cc: linux-mmc@vger.kernel.org
Acked-by: Linus Walleij <linus.walleij@stericsson.com>
Tested-by Zhangfei Gao <zhangfei.gao@marvell.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ccac56a..6711eb8 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -158,6 +158,10 @@
 #define MMC_CAP_NONREMOVABLE	(1 << 8)	/* Nonremovable e.g. eMMC */
 #define MMC_CAP_WAIT_WHILE_BUSY	(1 << 9)	/* Waits while card is busy */
 #define MMC_CAP_ERASE		(1 << 10)	/* Allow erase/trim commands */
+#define MMC_CAP_1_8V_DDR	(1 << 11)	/* can support */
+						/* DDR mode at 1.8V */
+#define MMC_CAP_1_2V_DDR	(1 << 12)	/* can support */
+						/* DDR mode at 1.2V */
 
 	mmc_pm_flag_t		pm_caps;	/* supported pm features */