Update armnn to rev 3 via SR 765890
    
    https://build.opensuse.org/request/show/765890
    by user dimstar_suse
    - Disable ArmnnConverter and ArmnnQuantizer packaging by default as it requires libQuantizer.so to be packaged, which is not yet
    - Package ArmnnConverter and ArmnnQuantizer
    - ExcludeArch %ix86: Parts of the build deps (tensorflow/bazel) are not supported on ix86