i2c-designware: use usleep_range() in the busy-loop

This is not an atomic context so there is no need to use mdelay() but
instead use usleep_range().
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

drivers/i2c/busses/i2c-designware-core.c

@@ -355,7 +355,7 @@ static int i2c_dw_wait_bus_not_busy(struct dw_i2c_dev *dev)
 			return -ETIMEDOUT;
 		}
 		timeout--;
-		mdelay(1);
+		usleep_range(1000, 1100);
 	}
 
 	return 0;