added necessary DT_DRV_COMPAT #define in akm09918 sensor decoder

[FlorianWeber1018]

The sensor decoder api was not available in fact that there was a define missing which links the decoder api to the DT. This PR should fix this issue.

[github-actions]

Hello @FlorianWeber1018, and thank you very much for your first pull request to the Zephyr project!
Our Continuous Integration pipeline will execute a series of checks on your Pull Request commit messages and code, and you are expected to address any failures by updating the PR. Please take a look at our commit message guidelines to find out how to format your commit messages, and at our contribution workflow to understand how to update your Pull Request. If you haven't already, please make sure to review the project's Contributor Expectations and update (by amending and force-pushing the commits) your pull request if necessary.
If you are stuck or need help please join us on Discord and ask your question there. Additionally, you can escalate the review when applicable. 😊

[FlorianWeber1018]

I have changed the commit so that the compliance checks should not fail now. Can anyone please restart the missing Tests?

[teburd]

Should be fine once CI passes

[MaureenHelm]

Can you rebase please? It seems the twister status never returned and I don't see a way to retrigger it

[FlorianWeber1018]

@MaureenHelm rebase is done

[github-actions]

Hi @FlorianWeber1018!
Congratulations on getting your very first Zephyr pull request merged 🎉🥳. This is a fantastic achievement, and we're thrilled to have you as part of our community!

To celebrate this milestone and showcase your contribution, we'd love to award you the Zephyr Technical Contributor badge. If you're interested, please claim your badge by filling out this form: Claim Your Zephyr Badge.

Thank you for your valuable input, and we look forward to seeing more of your contributions in the future! 🪁