n1sdp: update n1sdp pci quirk for SR-IOV support

Upstream-Status: Inappropriate [will not be submitted as its an hack required to fix the hardware issue]

The patch is taken from:
https://git.linaro.org/landing-teams/working/arm/n1sdp-pcie-quirk.git/tree/linux



Signed-off-by: Khasim Syed Mohammed <khasim.mohammed@arm.com>

VFs are not probing the vendor ID first, which is otherwise
the gate keeper for undiscovered devices. So any accesses using
a config space offset greater than 0 must be coming for an
already discovered device or from a VF that has just been created.

Also if Linux already has a struct pci_dev* for a given BDF,
this device is safe to access.

Skip the firmware table in these cases and allow accesses to
those devices. That enables SR-IOV support on the N1SDP board.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>