Enable cross compile for openbsd/amd64

[danieljakots]

Community Contribution License

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under the terms of the Apache 2 license.
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contributions to the project maintainers under the Apache 2 license.

Description

Enable cross-compile for openbsd/amd64

Motivation and Context

Bring back cross-compile for openbsd/amd64
after fixing the minio/dperf package upstream (minio/dperf@b21eebc)

How to test this PR?

make crosscompile must work

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Optimization (provides speedup with no functional changes)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• Fixes a regression (If yes, please add commit-id or PR # here) 22b7c8c
• Unit tests added/updated
• Internal documentation updated
• Create a documentation update request here