pci: Add support for filtering by function

This will be useful for PCI based drivers to integrate fully within
the device driver model, where they will have to provide the function
they are found.

Change-Id: I7d64a4c6727cee52cbcb743c859cda43ac1a853b
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
5 files changed