Finish generic hcd structure initialization and register
int usb_add_hcd(struct usb_hcd * hcd, unsigned int irqnum, unsigned long irqflags);
hcd
the usb_hcd structure to initialize
irqnum
Interrupt line to allocate
irqflags
Interrupt type flags
allocate the buffers of consistent memory, register the bus, request the IRQ line, and call the driver's reset and start routines.