net: aquantia: Save PCI config space during suspend callback

MSM PCI bus driver disables PCIe link during regular suspend. Save PCI
config space during AQC suspend callback so that the PCI framework will
not attempt to save config space during late suspend.

Change-Id: I3dd43a080958a43fa5a602c85e557cd7f8caef82
Signed-off-by: Jinesh K. Jayakumar <jineshk@codeaurora.org>