Update frequency plans

[johanstokking]

Summary

This updates the lorawan-frequency-plans to the latest version.

Changes

Include fix for US 902-928 MHz single channel frequency plans. Also includes a custom band single channel frequency plan.

Testing

Steps

1. Create gateway and end-device using one of the single channel frequency plans
2. Send join-request, observe join-accept
3. Send first data uplink message, observe data downlink message's MAC commands

Results

• Join should be accepted
• Join-accept should be sent on standard RX1 or RX2 frequencies
• Only one channel should be enabled as part of the CFList
• The data downlink message does NOT contain any MAC commands to configure (downlink) channels

Regressions

Existing deployments using these single channel frequency plans may see different downlink channels being configured. This should all go in-band via MAC commands.

Checklist

• Scope: The referenced issue is addressed, there are no unrelated changes.
• Compatibility: The changes are backwards compatible with existing API, storage, configuration and CLI, according to the compatibility commitments in README.md for the chosen target branch.
• Documentation: Relevant documentation is added or updated.
• Testing: The steps/process to test this feature are clearly explained including testing for regressions.
• Infrastructure: If infrastructural changes (e.g., new RPC, configuration) are needed, a separate issue is created in the infrastructural repositories.
• Changelog: Significant features, behavior changes, deprecations and fixes are added to CHANGELOG.md.
• Commits: Commit messages follow guidelines in CONTRIBUTING.md, there are no fixup commits left.