acpi: Move PCI functions to separate file

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Idc96b99da9f9037267c0bec2c839014b13ceb8cc
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51106
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Lance Zhao
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/acpi/device.c

@@ -5,6 +5,7 @@
 #include <acpi/acpi.h>
 #include <acpi/acpi_device.h>
 #include <acpi/acpigen.h>
+#include <acpi/acpigen_pci.h>
 #include <device/device.h>
 #include <device/path.h>
 #include <stdlib.h>