Merge remote-tracking branch 'kraxel/usb.74' into staging

* kraxel/usb.74:
  usb-tablet: Allow connecting to ehci
  ehci: Lower timer freq when the periodic schedule is idle
  usb: Allow overriding of usb_desc at the device level
  usb: Don't allow USB_RET_ASYNC for interrupt packets
  usb: Call wakeup when data becomes available for all devices with int eps
  add pc-1.4

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>