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ARROW-18162: [C++] Add Arm SVE compiler options (#14515)

As xsimd only supports fixed-size SVE, we have to specify vector size
explicitly on command line. And the binary can only run on hardware
with matched vector size. Otherwise, the code behaviour is undefined.
E.g., `cmake -DARROW_SIMD_LEVEL=SVE256 ..`
According macro `ARROW_HAVE_SVE256` and cmake variable are defined.

We can also leverage compiler auto vectorization to generate size
agnostic SVE code without specifying the vector size.
E.g., `cmake -DARROW_SIMD_LEVEL=SVE ..`

This PR also removes some unused Arm64 arch options.

Authored-by: Yibo Cai <yibo.cai@arm.com>
Signed-off-by: Yibo Cai <yibo.cai@arm.com>