xHCI: release spinlock when setup interrupt

Jiri Slaby reports spinlock is held while calling kmalloc(GFP_KERNEL)
and request_irq() in xhci_resume().

Release the spinlock when setup interrupt.

Reported-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>