uas: Add a quirk for rejecting ATA_12 and ATA_16 commands

And set this quirk for the Seagate Expansion Desk (0bc2:2312), as that one
seems to hang upon receiving an ATA_12 or ATA_16 command.

https://bugzilla.kernel.org/show_bug.cgi?id=79511
https://bbs.archlinux.org/viewtopic.php?id=183190

While at it also add missing documentation for the u value for usb-storage
quirks.

Cc: stable@vger.kernel.org # 3.16, 3.17
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

--
Changes in v2: Add documentation for new t and u usb-storage.quirks flags
Changes in v3: Fix typo in documentation
Changes in v4: Also apply the quirk to (0bc2:3312)
Changes in v5: Rebased on 3.17-rc5, drop u documentation, already upstream
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Documentation/kernel-parameters.txt

@@ -3541,6 +3541,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 					bogus residue values);
 				s = SINGLE_LUN (the device has only one
 					Logical Unit);
+				t = NO_ATA_1X (don't allow ATA(12) and ATA(16)
+					commands, uas only);
 				u = IGNORE_UAS (don't bind to the uas driver);
 				w = NO_WP_DETECT (don't test whether the
 					medium is write-protected).