Add support to load image from SFF-8020i type DVD

Fix bug of failing to load kernel from SAMSUNG DVD writer with SFF-8020i
command format. However, some time it fails with error information "ERROR
 ConditionCode 8/8ee4c040", but it successes to load next time. After timeout
wait time is extended, it successes to load disk image from CD/DVD disk every time.

sys/dev/usb/usb-ohci.c

@@ -2506,7 +2506,7 @@ int submit_common_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 	else
 		timeout = 2000;
 
-	timeout *= 40;
+	timeout *= 100;
 
 	/* wait for it to complete */
 #if 0
@@ -2782,7 +2782,7 @@ static int hc_reset (ohci_t *ohci)
 			return -1;
 		}
 //		udelay (500);		// changed for test liujl
-		udelay (1); // by xqch
+		udelay (1); 
 	}
 	return 0;
 }

sys/dev/usb/usb_storage.c

@@ -1169,7 +1169,7 @@ int usb_storage_probe(struct usb_device *dev, unsigned int ifnum,struct us_data
 	 * The SFF8070 accepts the requests used in u-boot
 	 */
 	if (ss->subclass != US_SC_UFI && ss->subclass != US_SC_SCSI &&
-	    ss->subclass != US_SC_8070) {
+	    ss->subclass != US_SC_8070 && ss->subclass != US_SC_8020) {
 		printf("Sorry, protocol %d not yet supported.\n",ss->subclass);
 		return 0;
 	}