virttest.test_setup: Add get_vf_num_by_id() function to PciAssignable class

Signed-off-by: Feng Yang <fyang@redhat.com>
virttest/test_setup: Update _get_pf_pci_id() function.

Get the PF PCI ID from self.pf_vf_info.
Return the first available PF if name is not set.

Signed-off-by: Feng Yang <fyang@redhat.com>
virttest:test_setup: update get_vf_devs() and get_pf_devs() function

get requested vf or pf from self.pf_vf_info list.

Signed-off-by: Feng Yang <fyang@redhat.com>
virttest.test_setup: Update PciAssignable class

In this patch have following update:
1. Delete self.type_list and introduce self.devices.
2. Update add_device() to support mac setting for VF.
3. Update get_devs() to use new get_vf_devs() and get_pf_devs().
4. Update kvm parameter by echo to /sys folder.
5. Support set mac for VF.
6. Update the way used to update kvm module parameter.

Signed-off-by: Feng Yang <fyang@redhat.com>
virttest.test_setup: Change docstring from Doxygen to sphinx in PciAssignable class

Signed-off-by: Feng Yang <fyang@redhat.com>
virttest.test_setup: Support vfio for pf/vf pci assign

Also add new function get_same_group_devs() to get devices in same
group.

Get device's driver from /sys/bus/pci/devices/[device id]/driver

Signed-off-by: Feng Yang <fyang@redhat.com>