mmc: core: Add default timeout value for CMD6

EXT_CSD[248] includes the default maximum timeout for CMD6.
This field is added at eMMC4.5 Spec. And it can be used for default
timeout except for some operations which don't define the timeout
(i.e. background operation, sanitize, flush cache) in eMMC4.5 Spec.

Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 9276286..2fcd24c 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -54,6 +54,7 @@
 	u8			rst_n_function;
 	unsigned int		part_time;		/* Units: ms */
 	unsigned int		sa_timeout;		/* Units: 100ns */
+	unsigned int		generic_cmd6_time;	/* Units: 10ms */
 	unsigned int		hs_max_dtr;
 	unsigned int		sectors;
 	unsigned int		card_type;