USB: EHCI: work around bug in the Philips ISP1562 controller
This patch (as1556) works around a bug in the Philips ISP1562 EHCI
controller. Although the controller claims to support frame-list
lengths smaller than the default of 1024 for its periodic schedule, in
fact smaller values don't work. A new quirk flag is added to indicate
when the bug is present, and if it is then the schedule size is left
at the default value.