PCI: iproc: Remove PAXC slot check to allow VF support

Fix previous incorrect logic that limits PAXC slot number to zero only.
In order for SRIOV/VF to work, we need to allow the slot number to be
greater than zero.

Fixes: 46560388 ("PCI: iproc: Allow multiple devices except on PAXC")
Signed-off-by: Jitendra Bhivare <jitendra.bhivare@broadcom.com>
Signed-off-by: Ray Jui <ray.jui@broadcom.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>