MdeModulePkg/FrameBufferBltLib: Use dynamic allocated line buffer
    
    https://bugzilla.tianocore.org/show_bug.cgi?id=339
    
    The patch uses dynamic allocated line buffer to reduce memory usage
    of frame buffer configure. (Original implementation uses 0x4000
    bytes for line buffer.)
    
    Contributed-under: TianoCore Contribution Agreement 1.0
    Signed-off-by: Ruiyu Ni <ruiyu.ni@intel.com>
    Reviewed-by: Feng Tian <feng.tian@intel.com>