cnss2: Fix pci suspend and resume sequence

Allow pci link suspend/resume only if target is powered on.
Otherwise pci link training will fail. Add a check if target is
powered on before suspending/resuming pci link.

Change-Id: I73b3003da4138155065ac3b8837d4147079ebc7e
CRs-Fixed: 2475839
Signed-off-by: Mahesh Kumar Kalikot Veetil <mkalikot@codeaurora.org>