cnss: Re-register PCI device after unregistration

When the PCIe link fails to come up, pci device is unregistered
but the pdev is not cleaned up and re-registration is not done
when WLAN driver registers with CNSS the next time. This may lead
to unregister the PCI device again if the PCIe link failure happens
again and could result in kernel panic. Fix it by cleaning up the
pdev in penv structure properly and re-register pci device the next
time.

Change-Id: I8b84e20035688c442e1f7fb257a7762ff562d015
CRs-Fixed: 624977
Signed-off-by: Komal Seelam <kseelam@codeaurora.org>