dts: Update mini_stm32h743.dts

[MasterKeyxda]

Enable I2C2
CPU_FREQ-480 MHz (commented out)

[github-actions]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[kartben]

It's technically more than just uncommenting since the other node would need to be commented out?

I would recommend including a brief mention about this in the board documentation, or, possibly better, creating a board variant?

[MasterKeyxda]

Yes the other node would need to be commented out.

I will update the doc to include details about replacing the node to access 480 MHz clock speed. I think a new board variant with different CPU speed might just confuse people.

I'll raise a new PR with CPU Freq and DOC change all in one.