Update loongson_intrinsics.h from v1.0.5 to v1.2.1
Update loongson_intrinsics.h from v1.0.5 to v1.2.1

Bug: webm:1755

Change-Id: Ib636d2aa521332b76b6aa1b0aa0a9005aafbf32b

ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,ShiftMediaProject/libvpx,ShiftMediaProject/libvpx,webmproject/libvpx,webmproject/libvpx,webmproject/libvpx