usb: hcd: use correct device pointer for dma ops

commit a8c06e40 ("usb: separate out sysdev pointer from
usb_bus") converted to use hcd->self.sysdev for DMA
operations instead of hcd->self.controller but forgot to do
it for one instance.

This gets caught when DMA debugging is enabled since dma map
and unmap end up using different device pointers.

Fix it.

Fixes: a8c06e40 ("usb: separate out sysdev pointer from usb_bus")
Reported-by: Carlos Hernandez <ceh@ti.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>