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/protocol.h b/include/linux/mmc/protocol.h
index c90b676..d740ab9 100644
--- a/include/linux/mmc/protocol.h
+++ b/include/linux/mmc/protocol.h
@@ -284,6 +284,7 @@
 #define EXT_CSD_BUS_WIDTH	183	/* R/W */
 #define EXT_CSD_HS_TIMING	185	/* R/W */
 #define EXT_CSD_CARD_TYPE	196	/* RO */
+#define EXT_CSD_SEC_CNT		212	/* RO, 4 bytes */
 
 /*
  * EXT_CSD field definitions