IC_ASSIGN_MMIODEV -> ACRN_IOCTL_ASSIGN_MMIODEV
IC_DEASSIGN_MMIODEV -> ACRN_IOCTL_DEASSIGN_MMIODEV
struct acrn_mmiodev has slight change. Move struct acrn_mmiodev into
acrn_common.h because it is used by both DM and HV.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>