PCI: Extend pci_reset_function() to support PCI Advanced Features

Some PCI devices implement PCI Advanced Features, which means they
support Function Level Reset(FLR).  Implement support for that in
pci_reset_function.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>