RFC: remove OPENMP_SIMD codepath config

[ralfbrown]

As we near the end of the SSE removal, we can also remove the remnants of a special code path for OpenMP autovectorization (since there are in fact no cases where we have both autovectorized and unvectorized code paths).

[TurboGit]

Thanks!

[MStraeten]

breaks macos m1 build since sse isn't available there:

[ 40%] Building C object bin/CMakeFiles/lib_darktable.dir/common/locallaplacian.c.o
/Users/martinstraeten/src/darktable/src/common/interpolation.c:559:3: fatal error: expected expression
  else
  ^
1 error generated.
make[2]: *** [bin/CMakeFiles/lib_darktable.dir/common/interpolation.c.o] Error 1

static inline void compute_upsampling_kernel(const struct dt_interpolation *itor,
                                             float *kernel,
                                             float *norm,
                                             int *first,
                                             float t)
{
#if defined(__SSE2__)
  if(darktable.codepath.SSE2)
    return compute_upsampling_kernel_sse(itor, kernel, norm, first, t);
#endif
  else
    return compute_upsampling_kernel_plain(itor, kernel, norm, first, t);
}

also in line 703, 1038
it seems the #endif needs to be after "else"

[ralfbrown]

You're right, and I had it that way other places....