usb-xhci: support xhci extended capabilities

commit 706c69e4 "xhci: fix port assignment" partially fixed the
usb port numbering.

Adding parsing of xhci extended capabilities, we can parse the
overlapped ports accordingly and have proper port numbering.

Signed-off-by: Nikunj A Dadhania <nikunj@linux.vnet.ibm.com>
2 files changed