As pci_devices.h is included by <page.h>, need to prepare pci_devices.h
for nuc6cayh and apl-up2 board.
Also the #error info in generic/pci_devices.h should be removed, otherwise
the build will be failed in sdc/sdc2/industry scenarios.
Tracked-On: #4458
Signed-off-by: Victor Sun <victor.sun@intel.com>
