MMIO read/write without memory order should be common ARCH, without
PIO support shouldn't use PIO APIs, so implement them as empty.
Tracked-On: #8807
Signed-off-by: Fei Li <fei1.li@intel.com>
Signed-off-by: Haoyu Tang <haoyu.tang@intel.com>
Reviewed-by: Yifan Liu <yifan1.liu@intel.com>
