USB: OHCI: don't allocate HCCA atomically

OHCI HCCA memory region is allocated from atomic DMA pool one time
during usb_add_hcd() and deallocated by usb_remove_hcd().

Do non-atomic allocation of OHCI HCCA and free some space in
coherent atomic DMA pool.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>