libata passthru: update cached device paramters

INIT_DEV_PARAMS and SET_MULTI_MODE change the device parameters cached
by libata.  Re-read IDENTIFY DEVICE info and update the cached device
paramters when seeing these commands.

Signed-off-by: Albert Lee <albertcc@tw.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 3e95e5c..703febb 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -151,6 +151,7 @@
 	ATA_CMD_WRITE_MULTI_EXT	= 0x39,
 	ATA_CMD_WRITE_MULTI_FUA_EXT = 0xCE,
 	ATA_CMD_SET_FEATURES	= 0xEF,
+	ATA_CMD_SET_MULTI	= 0xC6,
 	ATA_CMD_PACKET		= 0xA0,
 	ATA_CMD_VERIFY		= 0x40,
 	ATA_CMD_VERIFY_EXT	= 0x42,