BaseTools: report warning if VOID* PCD with {} value is not 8-byte aligned
    
    For VOID* Pcd with {} value, If platform developer wants to put in a
    specific hex offset value that is not 8-byte aligned for VOID * then we
    allow it with a warning message.
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Yonghong Zhu <yonghong.zhu@intel.com>
    Reviewed-by: Liming Gao <liming.gao@intel.com>