PCI/IA64: Allocate pci_root_info instead of using stack

We need to pass around info for release function.

Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Jiang Liu <jiang.liu@huawei.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-ia64@vger.kernel.org
Signed-off-by: Tony Luck <tony.luck@intel.com>