mmc: MMC sector based cards

Support for MMC 4.2 sector based cards. This tweaks the init a
bit and reads a new field out of the EXT_CSD.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index e45712ac..5d9896c 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -41,6 +41,7 @@
 
 struct mmc_ext_csd {
 	unsigned int		hs_max_dtr;
+	unsigned int		sectors;
 };
 
 struct sd_scr {