pci.h: move include into own wrapper

Split the include of hwaccess and libpci. There is no need to have pci.h
included in hwaccess.

Change-Id: Ibf00356f0ef5cc92e0ec99f8fe5cdda56f47b166
Signed-off-by: Thomas Heijligen <thomas.heijligen@secunet.com>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/58883
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>

atavia.c

@@ -21,6 +21,7 @@
 #include "flash.h"
 #include "programmer.h"
 #include "hwaccess.h"
+#include "platform/pci.h"
 
 #define PCI_VENDOR_ID_VIA	0x1106