usb: xhci: move initialization of the primary interrupter

usb: xhci: move initialization of the primary interrupter

Move the primary interrupter (0) initialization from xhci_mem_init() to
xhci_init(). This change requires us to save the allocated interrupter
somewhere before initialization. Therefore, store it in the 'interrupters'
array and rework xhci_add_interrupter() to retrieve the interrupter from
the array.

This is part of the ongoing effort to separate allocation and
initialization.

Signed-off-by: Niklas Neronin <niklas.neronin@linux.intel.com>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20250515135621.335595-12-mathias.nyman@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>