usb-xhci: scan usb high speed ports
usb-xhci: scan usb high speed ports

Current code scanned only the super speed ports. Add support for
scanning high speed ports as well.

Also re-org code to reduce duplication of code.

Signed-off-by: Nikunj A Dadhania <e2f4a5db9b4735182a88051d1e7a3599f9eac9db@linux.vnet.ibm.com>

open-power-host-os/slof,open-power-host-os/slof,open-power-host-os/slof,open-power-host-os/slof