PCI: Include pci.h for struct pci_ops definition

struct pci_ecam_ops embeds a struct pci_ops.  Explicitly request the
definition for struct pci_ops, otherwise gcc might complain:

  include/linux/pci-ecam.h:29:19: error: field 'pci_ops' has incomplete type
Signed-off-by: NMarc Gonzalez <marc_gonzalez@sigmadesigns.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

include/linux/pci-ecam.h

@@ -16,6 +16,7 @@
 #ifndef DRIVERS_PCI_ECAM_H
 #define DRIVERS_PCI_ECAM_H
 
+#include <linux/pci.h>
 #include <linux/kernel.h>
 #include <linux/platform_device.h>