Add M3 processors

[fxcoudert]

• Have you followed the guidelines in our Contributing document?
• Have you checked to ensure there aren't other open Pull Requests for the same change?
• Have you added an explanation of what your changes do and why you'd like us to include them?
• Have you written new tests for your changes? Here's an example.
• Have you successfully run brew style with your changes locally?
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• Have you successfully run brew tests with your changes locally?

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Sources:

• https://github.com/OpenMathLib/OpenBLAS/pull/4315/files
• https://github.com/Tencent/ncnn/blob/master/src/cpu.cpp

[MikeMcQuaid]

Thanks again @fxcoudert!

[p-linnane]

This results in a dunno value when running on M3. I've opened a fix here: #16393