mmc: export mmc_send_ext_csd()

Export function mmc_send_ext_csd() for reading the extended CSD register.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index 3e36566..bfcdaa6 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -718,7 +718,7 @@
 }
 
 
-static int mmc_send_ext_csd(struct mmc *mmc, u8 *ext_csd)
+int mmc_send_ext_csd(struct mmc *mmc, u8 *ext_csd)
 {
 	struct mmc_cmd cmd;
 	struct mmc_data data;