pci: pci-uclass: Add support for Alternate-RoutingID capability

If ARI capability is found on device, use it to update next function
number in bus scan and also helps to skip unnecessary bdf scans.

Signed-off-by: Suneel Garapati <sgarapati@marvell.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>