This is a follow up of
ARROW-8227. It aims to unify simd header files and simplify code.
Currently, sse header files are included in sse_util.h, neon header files in neon_util.h and avx header files included directly in c source file. sse_util.h/neon_util.h also contain crc code which is not used by cpp files #include them.
It may be better to put all simd header files in a single simd.h, and move crc code to where they are used.