System information (version)

• OpenCV => 4.2 (master branch)
• Operating System / Platform => Linux/ARM64 (aarch64 - NEON)
• Compiler => gcc

Detailed description

Enable CV_SIMD for cv::transform in the 16U case. My current configuration reports an x-factor of ~2.2 ~2.5 on the Mat_Transform::Size_MatType and Transform::OCL_TransformFixture tests, an no degradation in the other cases.

I will link a patch to this issue.

Issue submission checklist

• [X ] I report the issue, it's not a question
• [ X ] I checked the problem with documentation, FAQ, open issues,
  answers.opencv.org, Stack Overflow, etc and have not found solution
• [ X ] I updated to latest OpenCV version and the issue is still there
• There is reproducer code and related data files: videos, images, onnx, etc