PCI/AER: Factor out error reporting to drivers/pci/pcie/err.c

Move the error reporting callbacks from aerdrv_core.c to err.c, where they
can be used by DPC in addition to AER.

As part of aerdrv_core.c, these callbacks were built under CONFIG_PCIEAER.
Moving them to the new err.c means they will now be built under
CONFIG_PCIEPORTBUS, so adjust the definition of pci_uevent_ers() to match.

Signed-off-by: Oza Pawandeep <poza@codeaurora.org>
[bhelgaas: in reset_link(), initialize "driver" even if CONFIG_PCIEAER is
unset, update pci_uevent_ers() #ifdef wrapper]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c
index 6ace470..ffb9564 100644
--- a/drivers/pci/pci-driver.c
+++ b/drivers/pci/pci-driver.c
@@ -1535,7 +1535,7 @@ static int pci_uevent(struct device *dev, struct kobj_uevent_env *env)
 	return 0;
 }
 
-#if defined(CONFIG_PCIEAER) || defined(CONFIG_EEH)
+#if defined(CONFIG_PCIEPORTBUS) || defined(CONFIG_EEH)
 /**
  * pci_uevent_ers - emit a uevent during recovery path of PCI device
  * @pdev: PCI device undergoing error recovery