hwcap should actually be long.

I set it initially as long, since I referenced the Linux code, but it looks like it causes issues on FreeBSD, while long works fine. While researching this, I noticed that HWCAP is actually long everywhere, so you might want to switch Linux to long as well.

Pull Request Readiness Checklist

See details at https://github.com/opencv/opencv/wiki/How_to_contribute#making-a-good-pull-request

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  Patch to opencv_extra has the same branch name.
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