PCI: Guard pci.h with CONFIG_PCI

Adding PCI functions for romstage in pci.h breaks ARMv7 build without
this. Also fix two related includes to use pci_def.h instead.

Change-Id: I5291eaf6ddf5a584f50af29cf791d2ca4d9caa71
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5199
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/device/device_util.c

@@ -25,7 +25,7 @@
 #include <console/console.h>
 #include <device/device.h>
 #include <device/path.h>
-#include <device/pci.h>
+#include <device/pci_def.h>
 #include <device/resource.h>
 #include <string.h>