mmc: increase delay between ACMD41 retries

In the SD Specification, Power Up Diagram of Card figure, the Timeout
value for initialization process (ACMD41 command retries) is 1 second.
Align to match MMC cards (in mmc_send_op_cond()) and Linux kernel code,
and set the delay between ACMD41 command retries to 10ms.

Change-Id: I2e07cb9944e7d7b72f2d4b13e0505e6751458091
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/drivers/mmc/mmc.c b/drivers/mmc/mmc.c
index db6f3f9..b5f6a10 100644
--- a/drivers/mmc/mmc.c
+++ b/drivers/mmc/mmc.c
@@ -361,7 +361,7 @@
 			return 0;
 		}
 
-		mdelay(1);
+		mdelay(10);
 	}
 
 	ERROR("ACMD41 failed after %d retries\n", SEND_OP_COND_MAX_RETRIES);