st_smi: Read status until timeout happens

SMI driver read status fails because the control register could not be
overwritten. Instead, the read status should be tried until timeout.

Signed-off-by: Vipin Kumar <vipin.kumar@st.com>
Signed-off-by: Amit Virdi <amit.virdi@st.com>
Signed-off-by: Stefan Roese <sr@denx.de>

drivers/mtd/st_smi.c

@@ -187,7 +187,7 @@ static int smi_wait_till_ready(int bank, int timeout)
 	do {
 		sr = smi_read_sr(bank);
 		if (sr < 0)
-			break;
+			continue;	/* try until timeout */
 		else if (!(sr & WIP_BIT))
 			return 0;