uboot-imx

USB PCI-OHCI, interrupt pipe and usb event poll support

This patch added USB PCI-OHCI chips support, interrupt pipe support
and usb event poll support. For supporting the USB interrupt pipe, the
globe urb_priv is moved to purb in ed struct. Now, we can process
several urbs at one time. The interrupt pipe support codes are ported
from Linux kernel 2.4.

Signed-off-by: Zhang Wei <wei.zhang@freescale.com>