Dbc mem_init and mem_cleanup functions used xhci_hcd to get to the device
pointer. The device pointer can be accessed directly from dbc structure,
so pass a pointer to dbc as a parameter instead.

No functional changes
This change helps decoupling xhci and DbC
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20200723144530.9992-21-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>