Update CMakeLists NEON flag to reflect only AArch64 NEON optimizations #111

Job	Run time
CI ubuntu-latest baseline clang release	3m 4s
CI ubuntu-latest baseline clang debug	3m 20s
CI ubuntu-latest avx clang release	3m 11s
CI ubuntu-latest avx clang debug	3m 38s
CI ubuntu-latest avx2 clang release	3m 13s
CI ubuntu-latest avx2 clang debug	3m 20s
CI macos-latest baseline clang release	2m 42s
CI macos-latest baseline clang debug	3m 7s
CI macos-latest avx clang release	2m 41s
CI macos-latest avx clang debug	2m 51s
CI ubuntu-latest baseline gcc release	2m 55s
CI ubuntu-latest baseline gcc debug	2m 46s
CI ubuntu-latest avx gcc release	3m 13s
CI ubuntu-latest avx gcc debug	3m 5s
CI ubuntu-latest avx2 gcc release	2m 55s
CI ubuntu-latest avx2 gcc debug	2m 48s
CI windows-latest baseline msvc release	4m 33s
CI windows-latest baseline msvc debug	4m 8s
CI windows-latest avx msvc release	4m 32s
CI windows-latest avx msvc debug	3m 41s
CI windows-latest avx2 msvc release	4m 30s
CI windows-latest avx2 msvc debug	4m 24s
	1h 14m 37s

Provide feedback